Quick-Release Cage Mounts for the 30 mm Cage System

  • Flexure, Spring-Loaded, Swing Latch, or Magnetic Quick-Release Mechanisms
  • SM1-Threaded or Double Bored Mounts for Ø1" Optics
  • Drop-In Mounts for Insertion into Assembled Cage Systems


Right-Angle Adapter,


Cage Plate with
Magnetic Plate,


Flexure Retention,
Ø1" Double Bore

Application Idea

The DCP1 cage mount
can be inserted into existing
30 mm cage systems.


30 mm Cage Mount,
360° Rotation

Related Items

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Alternative Size Options
16 mm Quick-Release Cage Mounts
30 mm Quick-Release Cage Mounts
60 mm Quick-Release Cage Mounts


  • Compatible with Our 30 mm Cage System
  • Easily Insert or Remove Components Without Disassembling the Cage System
  • Accepts Ø1" (Ø25.4 mm) Optics

Thorlabs offers a range of mounts designed for quick and easy insertion of Ø1" optics into an existing 30 mm cage system. These mounts allow optics to be inserted or removed from an assembled cage system without affecting the alignment or assembly of the rest of the system. We offer five drop-in style mounts with different retention methods for application flexibility. We also offer one standard cage plate with a removable magnetic optic cell that allows optics to be removed or swapped into a cage system without changing the position of the cage plate, and a snap-on adapter plate that can mount perpendicular to the cage system.  

Cage System Overview

The Cage Assembly System provides a convenient way to construct large optomechanical systems with an established line of precision-machined building blocks designed for high flexibility and accurate alignment.

16 mm, 30 mm, and 60 mm Cage System Standards

Thorlabs offers three standards defined by the center-to-center spacing of the cage assembly rods (see image below). The 16 mm cage, 30 mm cage, and 60 mm cage standards are designed to accomodate Ø1/2", Ø1", and Ø2" optics, respectively. Specialized cage plates that allow smaller optics to be directly inserted into our larger cage systems are also available.

Standard Threads

The flexibility of our Cage Assembly System stems from well-defined mounting and thread standards designed to directly interface with a wide range of specialized products. The three most prevalent thread standards are our SM05 Series (0.535"-40 thread), SM1 Series (1.035"-40 thread), and SM2 Series (2.035"-40 thread), all of which were defined to house the industry's most common optic sizes. Essential building blocks, such as our popular lens tubes, directly interface to these standards.

An example of the standard cage plate measurements determining cage system compatibility.
Standard Cage System Measurements
Cage System 16 mm 30 mm 60 mm
Thread Series SM05 SM1 SM2
Rod to Rod Spacing 16 mm (0.63") 30 mm (1.18") 60 mm (2.36")
Total Length 25 mm (0.98") 41 mm (1.60") 71.1 mm (2.8")
Cage Components
Cage Rods 16 mm These rods are used to connect cage plates, optic mounts, and other components in the cage system. The SR Series Cage Rods are compatible with our 16 mm cage systems, while the 30 mm and 60 mm cage systems use ER Series Cage Rods.
30 mm
60 mm
Cage Plates 16 mm These serve as the basic building blocks for a cage system. They may have SM-threaded central bores, smooth bores sized for industry standard optics or to accommodate the outer profile of our SM Series Lens Tubes, or specialized bores for other components such as our FiberPorts.
30 mm
60 mm
Optic Mounts 16 mm Thorlabs offers fixed, kinematic, rotation, and translation mounts specifically designed for our Cage Systems.
30 mm
60 mm
Cage Cubes 16 mm These cubes are useful for housing larger optical components, such as prisms or mirrors, or optics that need to sit at an angle to the beam path, such as beamsplitters. Our cage cubes are available empty or with pre-mounted optics.
30 mm
60 mm
Post and Breadboard Mounts and Adapters Mounting options for cage systems can be found on our Cage System Construction pages. Cage Systems can be mounted either parallel or perpendicular to the table surface.
Size Adapters Cage System Size Adapters can be used to integrate components from different cage system and threading standards.
Specialized Components Thorlabs also produces specialized cage components, such as Filter Wheels, a HeNe Laser Mount, and a FiberPort Cage Plate Adapter, allowing a wide range of our products to be integrated into cage-mounted optical systems. Explore our Cage Systems Visual Navigation Guide to see the full range of Thorlabs' cage components.

Posted Comments:
mikael.malmstrom  (posted 2018-09-21 11:59:02.6)
It would be nice if you could design som sort of flip-mirror mount for the cage. I would like to place a easiliy removable alignement laser beam in the cage path
llamb  (posted 2018-09-22 11:28:57.0)
Thank you for your feedback. Our sliding filter mounts (such as part number CFS1) are cage compatible and should work for your application. The quick-release cage mounts on this page are designed for easy insertion and removal of an optic into your beam path. If a flip mount is preferred, I would recommend mounting a flip mount next to your cage system and removing one of the four cage rods, so the flip mount won't interfere with the cage system as it flips in and out.

Drop-In 30 mm Cage Mount with Flexure Lock

Drop-In Cage Plate
Click to Enlarge

DCP1 with ND Filter Snapping into an Existing 30 mm Cage Segment

  • Easy Insertion and Removal of a Ø1" Optic Within an Assembled 30 mm Cage System
  • Flexure Lock Securely Clamps to Cage Rods
  • Two Optic Retention Options
    • DCP1: SM1-Threaded (1.035"-40) with Two SM1RR Retaining Rings
    • DCP1A: Double Bored with Nylon-Tipped Setscrew

These Drop-In Cage Mounts allow Ø1" optics to be easily inserted into or removed from an assembled 30 mm cage structure. The cage mounts clamp to 30 mm cage rods across a diagonal, rather than to adjacent cage rods. To insert one of these mounts into a cage system, hold the mount diagonally and slide it between two cage rods, as illustrated in the photo to the right. Then twist the mount and snap it onto the cage rods before tightening the cap screw in each flexure clamp using a 5/64" (2.0 mm) hex key (not included).

The DCP1 features an SM1-threaded (1.035"-40) bore that can hold Ø1" optics up to 0.24" (6.1 mm) thick using the two included SM1RR retaining rings. Unlike our other quick-release cage mounts, the DCP1 can also be used with optics mounted inside SM1L03 lens tubes. For example, all of our SM1-threaded ND filters can be used with this cage mount. Longer lens tubes will block the cage mount from fitting into the cage system. The DCP1A features a Ø1" double bore with a nylon-tipped 5/64" (2.0 mm) setscrew for securing optics at least 0.22" (5.6 mm) thick. The setscrew retention design allows optics to be easily removed from the cage mount for quick optic changes.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
DCP1 Support Documentation
DCP1Drop-In 30 mm Cage Mount, Flexure Lock, SM1 Threaded, 0.40" Thick, 2 Retaining Rings
DCP1A Support Documentation
DCP1ACustomer Inspired! Drop-In 30 mm Cage Mount, Flexure Lock, Ø1" Double Bore, 0.33" Thick

Drop-In 30 mm Cage Mount with Spring-Loaded Clamp

QRC1A ApplicationClick to Enlarge
QRC1A Quick-Release Clamp Mounted Within a 30 mm Cage System
  • One-Handed Installation of a Ø1" Optic Within an Assembled 30 mm Cage System
  • Dovetail Design with Spring-Loaded Release Provides Smooth Clamping Action
  • Internal SM1 (1.035"-40) Threads Accept Optics Up to 0.14" (3.6 mm) Thick
  • Two SM1RR Retaining Rings Included

The QRC1A cage mount is equipped with a spring-loaded dovetail clamp that secures or releases the cage mount to two of the four ER rods in the cage structure. The cage mount has internal SM1 threading that allows for optics up to 0.14" (3.6 mm) thick to be secured with the two included SM1RR retaining rings.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
QRC1A Support Documentation
QRC1ADrop-In 30 mm Cage Mount, Spring-Loaded Clamp, 0.30" Thick, 2 Retaining Rings

Drop-In 30 mm Cage Mount with Swing Latches

STK01 Application
Click to Enlarge

STK01 Removable 30 mm Cage Mount Being Mounted Within a 30 mm Cage System
  • Easy Placement and Removal of a Ø1" Optic Within an Assembled 30 mm Cage System
  • Two Swing Latches Quickly Attach to Cage Rods
  • SM1 (1.035"-40) Tapped Hole Accepts Optics Up to 0.19" (4.9 mm) Thick
  • Two SM1RR Retaining Rings Included

The STK01 cage mount allows Ø1" optics to be inserted or removed from a closed 30 mm cage structure. The cage mount uses two swinging latches that are locked in place with four 5/64" (2 mm) hex locking screws. Optics 1" in diameter and up to 0.19" (4.9 mm) thick can be secured in the cage plate using the included two SM1RR retaining rings.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
STK01 Support Documentation
STK01Drop-In 30 mm Cage Mount, Swing Latch, 0.35" Thick, 2 Retaining Rings

Drop-In, Pivoting 30 mm Cage Mount with Flexure Lock, 360° Rotation

The CP360R snaps into pre-assembled cage systems, and can be used to mount optics both off-axis (such as a mirror mounted at 45°, shown on the right above) or on-axis.
  • Flexure Clamping Mechanism for Secure Cage Mounting without Disassembly
  • 360° Rotation for On- and Off-Axis Optic Alignment
  • SM1-Threaded (1.035"-40) Optic Cell Accepts Optics up to 7 mm Thick
  • Two SM1RR Retaining Rings Included

The CP360R(/M) drop-in cage mount allows for 360° rotation of a Ø1" optic within a 30 mm cage system. To insert one of these mounts into a cage system, turn the optic perpendicular to the optical axis, and snap the mount onto adjacent cage rods before tightening the setscrew in each flexure clamp using a 0.05" (1.3 mm) hex key (not included).

The optic can be rotated via the knurled knob or 3/16" (5.0 mm) hex, and the optic mount's pivot position can then be locked via a 0.05" (1.3 mm) hex. An engraved scale indicates the angle of the optic, with tick marks every 5°. Please note that when using with beamsplitters, the clear aperture will be an ellipse with a minor axis of approximately 0.315" (8 mm) when used at 45° AOI.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
CP360R Support Documentation
CP360RCustomer Inspired! Pivoting, Quick-Release, Ø1" Optic Mount for 30 mm Cage System
+1 Qty Docs Part Number - Metric Price Available
CP360R/M Support Documentation
CP360R/MCustomer Inspired! Pivoting, Quick-Release, Ø1" Optic Mount for 30 mm Cage System (Metric)

30 mm Cage Plate with Quick-Release Magnetic Plate

Click to Enlarge

The front plate of the CP44F assembly is held in place using magnets.
  • 30 mm Cage Compatible Back Plate
  • Magnetically Coupled Mounting Carriage
  • Accepts Ø1" (25.4 mm) Optics up to 0.20" (5.1 mm) Thick
  • Back Plate and Mounting Carriage Have Internal SM1 Threading
  • One SM1RR Retaining Ring Included

The CP44F consists of a back plate compatible with the 30 mm cage system and a mounting carriage (front plate) that is magnetically coupled with pairs of rare earth magnets to the back plate. For stability, precision, and repeatability, the mounting carriage contacts the back plate at three points. Each point of contact is a ball bearing on the mounting carriage resting in the groove formed by two parallel steel pins. Since the axes defined by the three sets of pins share a common point of intersection, the system is properly constrained (kinematic). The mounting carriage can be easily inserted or removed from the fully assembled cage system by separating it from the back plate, rotating it sideways, and then extracting it from the cage.

The internal SM1 threading allows components up to 0.20" (5.1 mm) thick to be secured in the mounting carriage with the included SM1RR retaining ring. Components with external SM1 threading, like the SM1A7 alignment guide, can be threaded onto the mounting carriage. However, components mounted in this way [OD = 1.2" (30 mm)] cannot extend more than 3/16" (4.7 mm) beyond the face of the mounting carriage without sacrificing the ability to remove the mounting carriage and component from a closed cage system.

Both the CP44F and CP44F-B cage rod through holes have side-located M4 locking setscrews, which can be secured using a 5/64" (2 mm) balldriver or hex key.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
CP44F Support Documentation
CP44F30 mm Removable Cage Plate, Front and Back Plate, Internal SM1 Threading
7-10 Days
CP44F-F Support Documentation
CP44F-F30 mm Removable Cage Plate, Removable Front Plate, Internal SM1 Threading
CP44F-B Support Documentation
CP44F-B30 mm Removable Cage Plate, Back Plate with ER Rod Holes, Internal SM1 Threading

30 mm Right-Angle Snap-On Adapter Plate

The CP360Q snaps onto ER rods and can be used to mount perpendicular cage systems, SM1 lens tubes, and Ø1" optics.
  • Mount a 30 mm Cage System onto Another 30 mm Cage System at a Right Angle
  • Accepts ER Series Rods
  • Snap-On Tabs Allow for Installation and Removal without Disassembling the Cage System
  • Internal SM1 (1.035"-40) Threading for Mounting SM1 Lens Tubes and Ø1" Optics
  • Eight Locking Screws with 5/64" (2.0 mm) Hex

The CP30Q Right-Angle Adapter Plate with Snap-On Tabs can be used to couple two orthogonal 30 mm cage segments. The front face has four Ø6 mm, 0.25" (6.4 mm) deep, blind holes for ER rods, and snap-on tabs on the back of the adapter (as shown to the right) allow the CP30Q adapter to be added and removed from an already assembled cage system without disturbing it. ER cage rods can be secured in each blind hole or snap-on tab by tightening the associated M4 x 0.7 locking screw using a 5/64" (2.0 mm) hex key or balldriver. The front face also has an internally SM1 (1.035"-40) threaded thru bore for mounting SM1 lens tubes or Ø1" optics up to 0.24" (6.1 mm) thick when two SM1RR retaining rings (not included) are used.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
CP30Q Support Documentation
CP30QCustomer Inspired! 30 mm to 30 mm Cage System Snap-On Right-Angle Adapter