Holder for mortise style practice lock to allow them to be easily clamped into a swivel vise and sit flush and allows to quickly slide locks in and out to change locks quickly without having to unclamp and clamp. It has a cutout on top to hold locks that have the bible tapped out like the learnlockpicking ultimate challenge lock, and is keyed to prevent the lock from rotating.

I designed it to have a slight snug fit, if you find it too tight, just scale it up a percent or two.