• Ø25 mm Filter in an SM1-Threaded Mount
• Mount Engraved with Part Number and Optical Density
• Ideal for Low-Power Applications (<1 Watt)
• Surface Flatness: λ10 (@633 nm)
• Absorptive Glass Reduces Multiple Reflections

This Mounted Absorptive Neutral Density (ND) Filter has a diameter of 1" (25.4 mm) and the mount is SM1 (1.035" -40) threaded and is also engraved with both the part number and the optical density. These mounts are compatible with a wide range to rigid construction optomechanical parts such as our cage systems and other lens tubes.

Please note that these products are not designed for use as laser safety equipment. For lab safety, Thorlabs offers and extensive line of safety and blackout products, including beam blocks, that significantly reduce exposer to stray light.

• Diameter Tolerance: +0.0/-0.25
• Clear Aperture: 90% Outer Diameter
• Surface Flatness (@ 633 nm): λ/10
• Surface Quality: 40-20 Scratch-Dig
• Parallelism: 10 arsec
• Optical Density (@ 633 nm): 2.0 ± 0.10
• Theoretical Transmission (@ 633 nm): 1%
• Substrate Thickness: 1.40 mm
• Substrate: NG9