Specifications: Center Material/Finish: Swiss CNC Machined Bar-Stock Steel Core, Hardened, Black Phosphate Lever Material/Finish: Investment Cast 8620 Steel, Black Phosphate Assembly Weight: 0.74 oz (center core, standard lever, short lever, and two set screws) Center Core Weight: 0.39 oz (with two set screws) Standard Lever Weight: 0.21 oz Short Lever Weight: 0.14 oz Country: Made In U.S.A. Features: Modular Assembly Ambidextrous Controls 0 - 90 -180 Ergonomic Lever Design Limited Lifetime Warranty Against Manufacturing Defects Dovetail Attachment Engineered for Ultimate Strength and Reliability Patent Pending Internal Locking Mechanism Eliminates Broken Screws Swiss CNC Machined Center for Ultimate Precision and Butter Smooth Operation Compatible with All Known AR Variant Triggers(1) (i.e. Hiperfire, Geissele, CMC, Timney, etc.) Compatible with All Known AR Variant Lower Receivers with or w/o Short-Throw Relief Cut and Markings. Package Contents: 1 x Full Auto Safety Center -  0°-90°-180 – Hardened Steel, Black Phosphate 1 x Standard Lever – Steel, Black Phosphate 1 x Short Lever – Steel, Black Phosphate 2 x 8-32x¼in Set Screws 5/64in Hex – Black Oxide 1 x 5/64in Hex Short Arm L-Key – Black Oxide 1 x Hardened SS Safety Detent – Black Nitride Finish 1 x Safety Selector Detent Spring