5APH69T-1 Kinematic Adjustable Polarizer Holder of Side Drive is similar to 5APH59T-1 Adjustable Polarizer Holder the only difference is that 5APH69T-1 has kinematic design and 5APH59T-1 has L-shaped flat spring. 5APH79T-1 Kinematic Double Optical Mount of Side Drive with Adjustable Polarizer Holder accepts two pieces of optics: on the platform (adjustable), and on the base (not adjustable). The fixing screw for optics on the base has a plastic tip. A retaining ring M27x1 to fix the optics is included. A tightening key 3K-25 for the retaining ring is available on request.

This mount is also compatible with Ø25.0 mm optics.

There you could see the difference between 5APH69T-1 and 5APH79T-1:

5APH69T-1 (back view)	5APH79T-1 (back view) - the base has aperture for second optics (not adjustable)