Ambuker RV Fresh Water Inlet Lockable 39mm Gravity Fill Cap — Spring Seal, Bayonet 75°

Keep your RV or camper's potable water supply secure and fast to refill with a lockable inlet designed for everyday use. This replacement kit from Ambuker combines a wide 39mm opening for quicker gravity fills, a spring-assisted cover and seal ring to prevent leaks and contamination, and a bayonet-style 75° inlet to stop overflow. The durable food-safe polypropylene construction resists weather and blends with modern RV exteriors.

How does this inlet speed up refilling on the road?

The large-diameter opening and optimized inlet angle let water flow quickly under gravity, reducing time spent at fill stations. The bayonet fit ensures a smooth connection and prevents accidental spills while pouring.

• 39mm wide fill port for higher flow rates
• 75° inlet angle designed to reduce splashing and overflow
• Bayonet-style fitting for secure, fast seating
• Vent holes that reduce back-spray while filling

Will the cover keep tank water clean and leak-free?

The kit uses a compression spring and a resilient sealing ring to hold the cap tightly closed, blocking rain, dirt, and insects. Together these parts help prevent external water ingress and reduce the chance of leaks when the vehicle is in motion.

• Spring mechanism maintains consistent closure pressure
• Sealing ring protects against rain and contaminant entry
• Waterproof fit minimizes dripping and loosening on bumpy roads
• Lockable design prevents tampering or accidental openings

How secure and convenient is the lock feature?

The inlet cap includes a keyed lock and two matching keys so you can restrict access to your freshwater supply. The lock is integrated into the cap’s profile for a clean look while still allowing quick unlocking when you need to fill.

• Comes with two metal keys for shared or backup access
• Locking mechanism keeps the hatch closed when unattended
• Streamlined design keeps keys and lock protected from weather
• Easy to operate: turn key and lift—no complex tools required

What should I know about materials and appearance?

Ambuker crafted the inlet from food-grade polypropylene to meet potable-water safety expectations and resist UV and road wear. The cap’s industrial-arc texture and clear nozzle markings make it simple to match existing RV styling and identify the fill point quickly.

• Food-grade PP for safe contact with drinking water
• Textured arc pattern for a modern, durable look
• Highly legible nozzle markings for quick identification
• Weather-resistant finish to maintain appearance over time

Who is this for? This replacement inlet is aimed at RV and camper owners, vanlifers, and small-trailer users who want a safer, faster and more secure fresh water fill point. It's a practical upgrade for anyone replacing a worn inlet, adding a lock for security, or improving the speed and reliability of routine refills without altering tank plumbing.