The Smith & Wesson M&P40 .40 S&W 20-Round Magazine features durable, heat-treated steel construction with a high-strength steel spring and injection-molded follower for smooth, reliable feeding. Numbered witness holes allow for easy round counts, and the removable floor plate ensures quick disassembly for maintenance. Product Specifications Manufacturer: S&W Model: M&P40 Caliber: 40 S&W Magazine Capacity: 20-Round