A 1x3x3 Gridfinity caddy for the Havalon Piranta replaceable skinning knives, which just happen to be very good at opening boxes and trimming prints.

There are two models: my recommend one, with a small thumb or finger depression to make removing it easier; and the same model without the thumb affordance. There is a little space around the depression to make it possible to remove the knife easily. On the off chance someone else has this knife and wants a tighter tolerance, let me know.

Havalon's product page for the Piranta-Edge and Piranta-Z (the two models for which this caddy should work): https://www.havalon.com/piranta-fitment-2