These MP7 armorer tools are what is needed to safely make repairs and service your MP7A1 or MP7A2. The set includes a mandrel, barrel nut wrench, a gas block/trigger assembly tool, and an ejector install tool. The mandrel protects the trunnion from damage when changing muzzle devices as well when removing the barrel nut. The gas block/trigger assembly tool is a dual purpose tool. It supports the gas block when installing or removing the gas block roll pin, but it also is the correct height for supporting the trigger when servicing the trigger safety latch. The ejector tool enables the compression of the ejector spring when installing the retaining pin.