WMD Guns Receiver End Plate Nitromet Black. First it mounts to the rear of the upper receiver to act as a dust cover to the gas system exit tunnel to keep dirt and debris from becoming lodged in the small openings formed by the cutouts. Second it provides a mounting platform for forward assist extension to protrude forward. This enables the shooter to have a solid flat platform under the forward assist to attach a thigh brace leg brace or handguard but with the stock end plate removed. The second purpose is cosmetic as it allows the end plate to be trimmed/drilled and that new end plate can be placed in the new cut/drilled area on the receiver. Second two grooves have been drilled and tapped at the two mounting holes to align the cut/drilled area and blend the endplate in with the upper receiver. This step is optional and not required for the thigh brace/end plate to properly engage the forearm. Specifications for WMD Guns Receiver End Plate: Manufacturer: WMD Guns Gun Make: AR Platform Package Contents: WMD Guns Receiver End Plate WMD Guns 1-NMREP: Receiver End Plate Nitromet Black