Freestanding or T-slot lens holder for 50mm lenses

This is a holder for 50mm lenses, using the lens grip profile from ThePlanetMike which is great for different lens thicknesses.

The holder is designed for use as free-standing lens stand on any flat surface, or for use on T-slot. In the pictures I'm showing it on 20mm t-slot. The anchor holes are just slightly undersized for M4 bolts so that you can tap them or drill them (I've tried both). For t-slot you just buy your preferred bolt and t-nut sizes and drill out the holes to fit with a hand drill (takes ~5 seconds each). The countersunk holes sink even allen bolt heads below the lenses (see pictures).