Lion Gears Swivel Stud/Rail Picatinny Adaptor Black Short. 16 in Color: Black Weight: 1.02 oz Features of Lion Gears Swivel Stud/Rail Picatinny Adaptors Low Profile Swivel Stud - Picatinny Rail Adaptor with 3 Slots and Adjustable Rail-Levelness Innovative Design Makes It Much More Stable Than Regular Swivel Stud Adaptor Lightweight (1.1oz) and Aluminum Reinforced Structure Adjustable Rail-Levelness Provides Up to 10 Degree Angle Compensation in order to Keep the Rail Parallel to the Barrel Quick and Easy Installation Material: Aircraft Aluminum Rail Type: Picatinny/Weaver Finish: Black Matte Package Contents: Lion Gears Swivel Stud/Rail Picatinny Adaptors Lion Gears LG-AS-S2W03: Swivel Stud/Rail Picatinny Adaptor Black Short