The 3 oz. MK-4 canister will deliver 20-25 short bursts of OC at an effective range of 10-12 ft.? The foam delivery method is a powerful and fast-acting foam that coats the face upon contact.? The .4% MC yellow banded canister indicates the major capsaicinoid level which is discharged at the nozzle at time of use.? The MK-4 is an ideal size for patrol officers to wear on a duty belt. This formulation has been tested and is non-flammable and Electronic Discharge Weapon (EDW) safe. Defense Technology First Defense OC Aerosols are produced in an ISO rated manufacturing facility. All Major Capsaicinoid percentages (MC%) are verified by an Independent Laboratory for quality assurance. The MK-4 is an ideal size for patrol officers to wear on a duty belt and will deliver 20-25 short bursts of OC at an effective range of 10-12 ft. This .4% MC OC aerosol product utilizes a foam delivery method is a powerful and fast-acting foam that coats the face upon contact.