Samson Sig 556 Short Piston Rail system Black. Lightweight aluminum construction features Picatinny rails at the 3 6 and 9 o'clock positions. Fits the Sig Sauer 556 Patrol and all 556 pistol variants. Specifications for Samson S.T.A.R. Sig 556 Short Piston Rail System: Manufacturer: Samson Gun Make: SIG Sauer Gun Model: SIG Sauer 556 Color: Black Finish: Anodized Gun Rail: Picatinny Handguard Material: 6061-T6 Aluminum Condition: New Included Accessories: Standard Fabric/Material: 6061-T6 Aluminum Gun Type: Rifle Quantity: 1 Features of Samson S.T.A.R. Sig 556 Short Piston Rail SystemFree float No need to remove gas block Forms continuous top rail 1913 Picatinny Mil-spec Precision laser engraving Made in New Hampshire USA Package Contents: Samson S.T.A.R. Sig 556 Short Piston Rail System What firearm models does the manufacturer say Samson S.T.A.R. Sig 556 Short Piston Rail System is compatible with? The manufacturer says that Samson S.T.A.R. Sig 556 Short Piston Rail System is compatible with SIG Sauer 556Samson Star-Sig-Patrol: Sig 556 Short Piston Rail system Black