Magazine extension for Benelli M1 and M2 shotguns. Adds three rounds to your capacity and works well with 18" barrels

No gunsmithing required to increase the magazine capacity of 12 gauge shotguns. Strong, lightweight extruded aluminum tubes are CNC-machined to provide uniform inside and outside tube dimensions for consistent and reliable feeding; installs in only minutes. Machined union nut attaches to the end of the factory tube; some models may require removal of factory magazine tube crimp. All models fit 12 gauge only; use the factory follower and install the extended magazine spring provided.