The Smith & Wesson M&P45 magazine is a factory original replacement magazine designed to increase the capacity of the S&W M&P45. The 14-round magazine holds four additional rounds of .45 ACP over the standard magazine and compensates for the additional length with an ergonomic grip extension sleeve. The Military & Police (M&P) magazine is made of steel and polymer and is made to stringent S&W specifications and tolerances using the same manufacturing and materials as the original equipment magazines to ensure perfect fit and operation.