This piston kit by Silencer Co. contains 5 pistons and three O-ring packs. The kit features .578×28 piston (1), 1/2″x28 piston (1), 16mm x 1 LH piston (1), 13.5mm x 1 LH piston (1), and 9/16″x24 piston (1). This kit is made to fit the Osprey and Octane suppressors by Silencer Co. SPECIFICATIONS Manufacturer SilencerCo Pricing Unit EA Model Osprey/Octane UPC 817272015294 SKU AC728 Width 3.9000 Length 7.7000 Height 2.6000 Weight 0.6000 Caliber 45 ACP Finish Black Nitride Series Piston Kit Size 5 Piece Type Piston