The Stop Box is an instant access handgun retention device that does not use batteries, electronics, or external keys. Our all mechanical design allows instant reliable access to your firearm when you need it the most, and is proudly made in America. Our unique patent-pending design is much like an inverted tumbler lock. Tumbler locks use a key to position tumblers to their proper alignment, allowing the barrel to rotate and unlock. The Stop Box uses five actuators located on the corner of the enclosure for fast and easy indexing.