Looking for the perfect lower to start your next bombproof build? The Knight's Armament SR-15 IWS Complete Lower Receiver is designed to provide AR aficionados with all the elements they need to construct their next go-to defensive rifle. Each Knight's Armament SR-15 IWS Complete Lower Receiver is built from forged aluminum and are built with the company's own safety selector, magazine release and bolt release, all fully ambidextrous. The lower is also equipped with the company's unique KAC 2 Stage match trigger.