Mid-Length Gas System - Results in lower recoil and better accuracy providing higher second shot hit probability. Official Smith & Wesson/Magpul Co-Branded, forged lower design- similar characteristics to the original Billet design. Flared Magwell for improved magazine insertion. Forward serrated edge of magwell for increased weapon control. Integrated trigger guard design for improved ergonomics and use with a gloved finger without having to manipulate the trigger guard out of the way prior to usage.