The ASP (Armament Systems and Procedures) Palm Defender provides a professional strength OC spray in a low profile, devastatingly effective protection system. The ASP palm defender is solid metal and built to last. This not one of those plastic OC sprays that will crack and break in you pocket. It has an OC spray insert that is replaceable will refill cartridges. The aerosol inserts contain 10% Oleoresin Capsicum which delivers Two Million Scoville Heat Units in strength.