Invert can and make sure charging nozzle is perpendicular to the valve stem. Press nozzle into Mag for 2-3 seconds. Repeat as necessary until Mag is full. Valve misalignment will cause gas leak when charging and result in an inadequate charge. DO NOT PUNCTURE. DO NOT LEAVE CANISTER IN TRUNK OR VEHICLE. DO NOT EXPOSE TO HEAT, SPARKS AND OPEN FLAME. DO NOT LEAVE IN DIRECT SUNLIGHT. DO NOT STORE AT TEMPERATURES ABOVE 120F (49C)