50 Round 22 long rifle drum magazine fits Smith & Wesson M&P15-22. The drum features a modular design with an interchangeable feed tower, allowing it to be configured to function in most AR-15 rimfire conversions, the S&W M&P15-22, or the Ruger 10/22 by installing the appropriate feed tower (M&P15-22 Feed Tower Included, others sold separately). Polycarbonate PC construction withstands heat and wear for durability and long service life.Notes:This Drum Magazine has the S&W M&P15-22 Feed Tower installed, and does NOT come with either the AR-15 Rimfire Conversion or Ruger 10/22 Feed Towers (sold separately).