Our UPR 16/4 Universal Picatinny Rail provides enhanced position versatility for your Tactical Lights and lasers and any other Picatinny compatible accessory. Features: Compensates the Handguard's Angle To Allow Desired Parallel To Barrel Positioning Provides Quality Upgrade and Mounting Options MIL-STD 1913 Manufactured with Durable Reinforced Polymer Composite Compatibility: All M16/M4/AR15 Handguards