Lens cap holder (67mm) for Peak Design slide strap

Been wanting a lens caps holder like this for a while after losing too many to pockets, backpacks, setting them down and forgetting, etc.

The lens cap just clips in and is held by friction, I tried some kind of overhang to lock it in but couldn't get the tolerances to work, it's a very thin margin. It's a fairly sturdy holder regardless, it'll keep the cap secure through shaking the strap and moving around normally, sliding from front to back carry etc. If you REALLY shake the strap I have got the cap to pop out, but am confident with the holding strength under normal situations.