The Taylor Freelance +8 magazine for the Smith & Wesson M&P in 9mm Luger/ 40 S&W pistol is constructed of black Delrin. This magazine extension will increase the capacity of your factory magazine by 10 rounds in 9mm and 8 rounds in 40 S&W. The length of the magazine with the extension will not exceed the IPSC Open Class 170mm length rule when used on full size M&P magazines. The extension works with the stock magazine follower and includes a custom length Wolff extra power spring for reliable operation.