The Strike Industries Advanced Receiver extension brings an updated aesthetic and increased functionality to an often neglected, yet highly important component of the AR-15/AR-10 weapon system. The scalloped surfaces decrease friction with tight fitting stocks, and shaves weight while retaining mass in critical stressed areas. Further enhancements include a supported buffer retaining tab that also serves to more easily index your receiver extension. The SI Advanced receiver extension is machined from 7075-T6 aluminum for much greater strength than your standard 6061 tubes. Upgrade your AR and stand out from the pack with the SI Advanced Buffer Tube. Product Spec - Materials: 7075-T6 Aluminum - Length:7.28" - Tube Dia. 1.145" - Available Colors: Black | Blue | FDE | Red - Weight: 3.8oz Package include - 1x 7-Position Advanced Receiver extension Features - 7-position MIL-SPEC diameter buffer tube - Fits onto any standard AR-15 receiver. - Finer length of pull adjustment. - Supported buffer retainer - Compatible with Strike Industries Pit Viper Stock NOTE: Not compatible with rifle length buffers or rifle length springs. Cannot work with the A5 buffer system. Internal length of buffer tube is the same as a standard carbine buffer tube