The Milwaukee 1-1/2-inch 18-gauge 1/4-inch narrow crown Fasteners feature a galvanized finish for longevity, and have been rigorously tested and proven to comply with building codes as described in the ESR-1539 evaluation report. The fasteners are also guaranteed to meet or exceed applicable ASTM standards. The fasteners are designed to fit Milwaukee 7155-21, Duo-Fast, Hitachi, Porter-Cable, Ridgid, Senco, and most other 18-gauge 1/4-inch crown finish staplers.