Beretta 1301 Tactical Gen 1/Gen 2 Models, A300 models with a 5 round factory capacity - Complete Package For Beretta models with a 5-round factory magazine tube Features MXT magazine extension designed exclusively for the 1301 Tactical Beretta 1301 extension increases magazine capacity to 7 rounds (capacity determined with 2 3/4a ^2 shells and may vary with shells of differing length) This package has a special +2 extension tube is exclusive to this kit and not available separately. (If you try to build your own kit our standard +2 will extend about 1/2a ^2 past the muzzle) Barrel clamp kit includes 1301 Tactical-exclusive clamp, Picatinny rail, Mfg: Nordic Components