Works with 3-1/2" and 4" residential hinges with 1/4" hinge pins. Pin on door stop is 3/16" diameter. Bumperless design eliminates damage to doors and trim. Ultra-low profile in popular designer finishes. Installs in seconds. No tools required. 3/8" gap required between hinge barrel and adjacent trim. Hinge mounted to fit all doors. Won't work up like conventional hinge-mounted products. Made from strong carbon steel.