The 9852 Classic Corner Mirror Mount centers a 2.0 inch (50.8 mm) diameter optic at the fourth corner of the square formed with the three adjustment screws, allowing you to get tilt, tilt without translation, and pure translation all in a single mount. For pure translation, simply turn all knobs the same amount. A 1° rotation in one knob results in only 0.0012° tilt in the face plate. For tilt without translation, use two knobs, or for applications when translation is less important, adjust the tilt with just one knob. The proprietary, precision, knob actuated 1/4-80 screws give you increased durability, better repeatability, and even more precise adjustment than comparably priced mounts. Because the optic sits close to the edge of this mount, it is ideal for applications where clearance is an issue.  The 9852 is designed to hold mirrors, lenses or beam splitters having a 2-in. or 50 mm diameter and, due to its threaded retaining ring and spacers, can hold mirrors as thick as 0.50 in.(12.7 mm) and as thin as 0.02 in.(0.5 mm).