The Strike Industries Advanced Receiver extension brings an updated aesthetic and increased functionality to an often neglected, yet highly important component of the AR15/AR10 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.