Rack mounts on any clean, flat surface. Has foam tape for easy mounting or can be mounted with screws. Holds pistols upright with scopes, or upside down. Holds most revolvers and semi-automatics-from small single stack pocket pistols, PPKs, 1911s, Barettas, Glocks to large frame revolvers including the 500 S&W Magnum. Strong steel construction for years of service. Dimensions-3"H x 4"W x 3" D