Mag tube fit benelli m4 perfectly - Black River Manufacturing Benelli M4/SBE 3, 7 Round, Magazine Extension Kit

I added this 7 round tube to my Benelli M4 and it was a direct replacement. The carbon fiber is nice, strong and light weight. Black finish on the metal ends matched color well. Came with new spring and follower. You do have to heat the original mag tube with a heat gun to loosen the red locktite about 5-10 minutes on medium heat (Search youtube). The only thing I found negative was the optional clamp on rail attachment didn't fit as well as it could have. It's kind of tight between the mag tube and the barrel and I didn't want to force it and scratch the barrel so I opted to leave it off as I hadn't planned on using it anyways. It has 2 tube spacers that can be removed and it will fit without them. Overall very pleased with the Carbon Magazine tube.