Air Vent Hidden Safe Blends in anywhere with the look of a normal vent on the wall, it’s great for home, office or business. High Speed Security. Shelf is the fastest access safe on the market. It is a super quick installation in 5 minute. Instructions and template are right on the box. It has a back up battery option. It has an easy way to open the quick Shelf even if the batteries die. Large compartment approximately 14″ x 3″ x 6.25″ of storage space.