Leapers UTG Model 4/15 Flat Top Riser Mount .5", Black - MNT-RS05L. Low Profile Riser Mount for Rifles with Picatinny/Weaver Rail, 5.7" Long Picatinny Rail 13 Slots and STANAG Feature for Flexible Accessory Application, Clever Retention Thumb Nuts and Locking Plate for Quick Easy Installation, Precision Made from Aircraft Aluminum with Matte Black Anodizing, 0.5" Saddle Height with See-through Design.