Prusa Bear toolbox (Bear? here: https://github.com/gregsaun/prusa_i3_bear_upgrade) . Works with 20mm V-slots, doesn't really make use of the V-slot interface but has a snug fit. See pictures.
Was originally posted by me at https://www.thingiverse.com/thing:3544468
To mount: backside first then tilt the front down
To unmount: pull front side up, backside will follow
The author marked this model as their own original creation.