Upgrade your AR with the lo-profile gas block. Designed to fit barrels with a .750 diameter this high-quality piece helps to improve the performance of your firearm. Its made from durable materials and easy to install making it a must-have for any AR owner. Plus its low-profile design wont add unnecessary weight or bulk to your rifle. 2 Set Screws (requires a 3/32 Allen wrench) 1 Roll Pin 10-321/4 socket screw cone point alloy in black