PSA B5 Systems EPT Lower Build Kit with SOPMOD Enhanced Stock is a lower build kit designed to finish your AR-15 lower. Includes Mil-Spec SOPMOD Enhanced Stock, Type 23 P-Grip from B5 Systems, Mil-Spec buffer tube assembly, and a PSA Classic Lower Parts Kit. Designed to finish a lower receiver with a stock, including a fire control group, buffer tube assembly, and assorted lower parts such as takedown pins, bolt catch, magazine catch, and safety selector.