The 9771-M EC Platform Mirror Mount is ideal for applications where space is tight, and you want an optic mount that is also easy on your wallet. You get a 3/8 in. thick frame, our high-quality 6-80 Knob adjustment screws, and M4 threaded holes that allow vertical mounting for holding 12.7 or 25.4 mm diameter mirrors or horizontal mounting for holding cubes. For odd sizes, you can bond the optic to the front plate.