Peephole, peekhole, spyhole, doorhole, magic eye, magic mirror, door viewer shutter / cover

A simple peephole cover, basic dimensions are shown in the images below. I attached CAD model in STEP and SLDPRT for adjustments. The protrusion on the back side of the cover is designed to fit into a hole that is 2,7 mm in diameter and 1 mm thick. It does not fall down by itself but can be adjusted to do so if desired.