Redefine your defense tools with the ASP D1 Heat and Test Inserts. Precision-machined from aerospace aluminum and solid brass, these Inserts go beyond standard aerosol defense products. The Insert is engineered to house a self-contained, replaceable OC (Oleoresin Capsicum) canister that delivers six 1/2-second bursts at an effective range of five feet. It incorporates a specially developed valve system and patented dispensing mechanism. The entire mechanism is secured with an O-ring seal. The "Heat" variant contains the maximum strength, law enforcement-grade OC: 10% Oleoresin Capsicum, 1.33% major capsaicinoids, and two million Scoville Heat Units (SHU). Test inserts filled with harmless, inert aerosol are also included for practice use. Compatible with both the ASP Metro D1 and Sport D1 Defenders.