In our implementation of Pekelsky's design, the baseplate is the same as the 45° beam-splitter mount described above, with added holes to accept the wire spring and the adjustment screws. The mounting plate is 3D-printed from PLA, and is shaped to fit snugly within the optical cage. The mirror is inserted into a central hole in the mounting plate, where it rests against a lip and is held in place by means of a rubber-tipped M3 set screw. Two self-tapping M4 adjustment screws allow the orientation of the mirror to be adjusted about the horizontal and vertical axes.