I made my own. It fits in the back of my Landcruiser and locks down on the orignal brackets that the rear seats latch onto. The two sliding drawers are each 18" X 40" X 7.5". The whole unit is seam welded 11 gauge steel. The drawer fronts are 11 ga 316 stainless. Each drawer front is backed up 1/4" Astroloy plate. The drawers are secured with Corbin Russwin 6 pin high security cylinders operating high security deadbolt locks with 3/4" X 1" case hardened stainless steel latchbolts. I carpeted the entire unit but the polished SS drawer fronts. I keep 4 doubles in SKB takedown cases in one drawer. Three different gauge shells, 2 vests, 2 E-collars, first aid kit,an insulated coat, chaps, several hats, pairs of gloves, and have room for more. My wire dog crate straps down to the vault. I left the unit in the Landcruiser from Sept. through the end of March. It is sure convenient not to load and unload all that stuff every time we get out. This year I am going to remove the rear seats completely rather than folding them up. I have to make the new vault run from wheel well to wheel well. I'll be adding a third drawer with the extra width. I have to add another crate for my new pup to ride in.
Here is a picture I took last year.