All steel construction Multiple locking points Ergonomic steel thumbscrew to enhance function and securing Black oxide finish Custom adapter bolt swivel base with spacers 2 locking swivels included 1 inch loops Manufactured in the United States Made of durable, steel with a black oxide finish, this swivel set comes with a 3/4 inch rear swivel stud and spacer, along with a custom adaptor bolt swivel base with spacers for an exact fit. Also included in the kit are two Grove Tec locking swivels that have the easy adjust thumbscrew for security and function with a 1 inch loop. Mfg: Grovtec Us SPECS: 1 inch loop, All steel construction, Black oxide finish. GTSW16 - 3/4 inch rear swivel stud and spacer, Custom adaptor bolt swivel base with spacers, 2 locking swivels. Made for 7400 & Four Autoloaders. GTSW18 - 3/4 inch rear swivel stud and spacer, Custom adaptor bolt swivel base