6-12mm Inline One-way Valve Non-return Check Aluminum Fuel Water Gas Air Vacuum
6mm (1/4"")、8mm (5/16"")、10mm (3/8"")、12mm (1/2""). Suitable for gasoline, diesel oil, bio/vegetable oil, paraffin/kerosene, etc. ". The service life of aluminum head is longer than that of plastic head.