Strike Industries Advanced Receiver Extension Buffer Tube The Strike Industries Advanced Receiver Extension is designed to increase the functionality of your AR-15/AR-10 weapon system. The scalloping detail on the surface works to decrease friction with tight fitting stocks and shaves weight while retaining mass in critical stressed areas. It features a supported buffer retaining tab that also allows you to easily index your receiver extension. Machined from 7075-T6 aluminum, this buffer tube is durable and will give you a customized look and feel.Featuresa 7-position MIL-SPEC diameter buffer tubea Fits onto any standard AR15 receiver.a Finer length of pull adjustment.a Internal length of buffer tube is the same as a standard carbine buffer tubeNote: This is not compatible with rifle length buffers or rifle length springs and cannot work with the A5 buffer system.