These 11 Gram canisters can be used all by themselves or with the (included) Key Chain Release Units. Either way, you are still getting famous FOX''s formulas. These unassuming 'mini' sprays are ideal for carrying in a shirt pocket, boot, vehicle or for hand-held concealment for close-in encounters. Their size is small, but the effects are big. They come in both canister and multi-color key chain units.