One piece body, machined from heavy duty aircraft-grade aluminum alloy. Mount replaces the dust cover. Just slide it on and snug the screws! Superior design with integral sliding rail system allows for quick and easy installation and does not require locking plates. Integral Picatinny rail takes standard Weaver type rings and has 21 slots for scope or accessory placement. Optimum height/width clearance for all popular scopes. Larger ejection port for optimum performance. Inch and metric compatible! Accommodates aftermarket T-Bars for SUITS. Lower Weaver base allows the use of iron sights. Lifetime replacement guarantee!