The new Upper Receiver AR-15 Action Rod is a must have tool when building any kind of AR-15. The tool eliminates stress on the upper receiver when installing a barrel and works on all AR-15 barrels with standard barrel extensions. The rod also works on both forged and milled upper receivers, and the design enables you to work on the upper with no need to remove your sights or optics. A simple twist and lock design makes it easy to hold the tool in place when working, and a gas port index rod is included in the design.