A coupling for attaching a canister to an appliance comprises a first connector on the canister comprising screw threads and a groove and a second connector on the appliance that comprises a slip ring. The slip ring retains the canister on the appliance. An appliance comprises a canister having screw threads. A coupling connects the canister to the appliance separate from the screw threads where the coupling locks the appliance to the canister without rotating the appliance relative to the canister. The coupling locks the appliance to the canister when the canister is moved axially relative to the appliance. A canister is provided that has a connector comprising a set of screw threads for attaching the canister to a first type of appliance, and a groove for attaching the canister to a second type of appliance. A method of connecting a canister to an appliance is also provided.