The Official Qube compensator is the first pistol compensator that doesn't require set screws. The compensator mount threads onto the barrel first and gets torqued down with a wrench. The Official Qube compensator body slides over the top of the compensator mount and shoulders against a taper. The lock nut threads onto the compensator mount and pinches the Official Qube compensator body against a second taper and locks it down which prevents rotation.