UTG Flat Riser Mount Model 4/15 for Picatinny or Weaver rails 5.7.Fits rifles with Picatinny or Weaver rails. 5.7 inch top Picatinny rail with 13 slots and STANAG feature for flexible accessory application. Clever retention thumb nuts and locking plate for quick and easy installation. Precision made from aircraft aluminum with matte black anodizing. 0.83 inch saddle height with see-through design.