This cap has secure sealing and easy finger tip operation. These caps are made from the highest quality modern engineering plastics with Viton o ring seals (which can be easily replaced if you should ever need to do so.) This cap is non vented and recommended to keep the fuel in, the water out and in the locking version, other unwanted items out of your tank. Size: 70 mm O.D.; Wt: 80 grams. Manufactured by SPRL.