SureShell Polymer Carriers are injection molded glass filled polymer yokes, secured to the receiver by a lightweight aluminum back plate with brass threaded inserts. Available only in a six-shell configuration, the polymer carrier also includes an innovative dual rubber friction system that reliably holds shotshells in place. These shotshell carrier/rail systems mount by using the drilled and tapped holes on top of the shotgun's receiver. The mounting screws for the Benelli M1, Benelli M2 Tactical and Benelli M4 SureShell carriers with rails are patterned on the factory screws for the Benelli M4's optics rail. Mounting hardware is included.