The Wheeler Upper Receiver Action Rod AR-15 reduces stress on upper receiver during barrel installation or removal. The gas port index rod assures perfect barrel nut and gas tube alignment. Clamp the rear of the action rod into a vise. The rear twist knob rotates the front bolt face lock and engages the rod securely with the barrel. Work on upper receiver from multiple angles without slipping in vice jaws. Lock into barrel extension Works on all AR-15's with standard barrel extensions Gas port alignment tool No removal of optics or sights required Work on upper receiver from multiple angles without slipping in vice jaws