• Directly Mounts Ø25.4 mm Optics up to 12.7 mm Thick
• Scale can be Rotated Independent of Mounted Optic for Alignment
• Switch Between Continuous Rotation and Discrete Rotation in 15° Increments
• 2° Gradation Marks, Numbered Every 20°
• 5 Arcmin Vernier Scale
• Ideal for Polarization Optics
• Post Mountable via M4 Tap
• Unpackaged Weight: 131 g

The RSP1X15/M rotation mount features both continuous 360° rotation and 15° stepped rotation for Ø25.4 mm optics. The optic is retained in the central SM1-threaded bore using the included SM1RR retaining ring. The top of the mount has a setscrew that, when loose, allows for continuous 360° of smooth rotation. Tightening the setscrew engages a detent mechanism that forces the mount to rotate in discrete 15° increments. In addition, the engraved scale can be unlocked and rotated independently of the optic so that the markings can be aligned with respect to the mounted optic. For example, the zero of the engraved scale can be aligned with the fast axis of a wave plate or the polarization axis of a linear polarizer. To help with the alignment, an engraved arrow extends the zero mark all the way to the outside edge of the SM1 threaded bore used to mount the optic.