A (parametric) buckle that you can attach to your camera strap, which lets you (hopefully) stop losing your lens cap.

The STL is sized for a 77 or 58mm lens cap, and a ~44mm strap width.

The printing layers make for a great friction catch for the lens cap. But there's a designed-in lip overhang to make it a little more aggressive.

Modified from original file: https://www.thingiverse.com/thing:9860