🚐Material: The water filler cap is made of sturdy food-grade PP plastic, which is strong and rust-proof, durable, reducing the frequency of replacements and lowering your costs. 🚐 Lid design: The water filler cap has a snap lid, a 0.3 \" vent for faster filling, and a 1.6 \" barn coupling. At the same time, the design with spring and sealing ring can effectively prevent water leakage and loosening. 🚐Waterproof with lock: The water filler plug is equipped with a lock and two keys, which is convenient for water storage and can guarantee the safety of water outdoors. 🚐Widely applicable: The water filler cap is suitable for all RVs with a door panel thickness of 30-40 mm/1.18-1.57 inches, including other caravans, motorhomes, boats, etc. 🚐Customer service: We sincerely provide the best service. If you encounter any problems when using the product, please contact us in time and we will provide you with support.