This is a two part square (50.8 mm^2) filter stand for the photonics lab at Michigan Tech. The square filter is placed into the slots on the top half of the mount which is then placed into the bottom half and held in place with a set screw. The hole is designed for a 1/4" set screw; a respective nut is to be press fit in. The lab has requested for a spot to place labels on the stand so a standard size label black was added to the top mount.