The MR-15 is an AR-15 variant constructed of 6061-T6 aircraft grade aluminum and finished in proper Mil-8625 Type III (3) class 2, hard coat anodize. The correct hard coat anodize leaves a finish stronger than tool steel to stand up to the most demanding applications. The MR-15 sports a traditional trigger well opening to allow for a classic bottom plate for ease of operation in both warm and winter climates, where room for a gloved finger is a necessity. This product is proudly 100% made in the U.S.A.