Unlike common throwaway aerosol can defense products, ASP Defenders are highly-engineered dispersion devices that use a proprietary, replaceable OC (Oleoresin Capsicum) Insert. These Inserts are precision-machined from aerospace aluminum and solid brass, and incorporate a specially-produced valve system and patented dispensing mechanism. The entire unit is O-ring sealed.

This Insert is compatible with ASP Key Defenders, and contains approximately six 1/2-second bursts.