Sailong RV Water Inlet Funnel 4" Wide-Mouth for 1¼" Inlets — Locking PETG, Hands-Free Fill

The Saillong 4" wide-mouth RV water inlet funnel is a 3D-printed locking fill adapter made for 1¼" (31.75mm) gravity water inlets that lets you fill your fresh water tank hands-free and without spills.

Designed for RV owners, campers and travel-trailer enthusiasts, this funnel replaces flimsy funnels and awkward adapters with a rugged PETG component that locks into the standard 1¼" inlet. Its wide 4-inch opening accepts jugs, buckets and higher-flow hoses while a rotating cam-lock secures the funnel to prevent slipping, splash-back and wasted water. Built for frequent use, the 3D-printed PETG resists cracking and temperature-related brittleness so it performs reliably whether you’re parked in summer heat or winter chill.

How does the locking mechanism make filling easier?

The rotating cam-lock collar secures the funnel to the RV’s fresh water fill adapter so you don’t have to hold it while you pour. Once engaged the funnel stays in place, allowing single-person operation and eliminating the need for extra hands or constant adjustment.

• Rotating lock clicks into the inlet for a secure, hands-free fit
• Quick-release cam collar detaches in seconds with no tools
• Prevents slipping and reduces spills at busy fill stations

Will this funnel fit my RV’s inlet?

This funnel is made to match the most common RV gravity water inlet size — 1¼" (31.75mm) — so it works with standard fresh water fill adapters on many RVs, travel trailers and campers. No extra adapters or modifications are required for compatible inlets.

• Specifically sized for 1¼" (31.75mm) gravity water inlets
• Designed to connect directly to standard RV fresh water fill adapters
• Ideal as a direct replacement or upgrade to improvised funnels

What materials and durability can I expect?

The funnel is 3D printed from PETG, a plastic chosen for toughness and environmental resistance. PETG resists cracking, splitting and brittleness across typical camping temperature ranges, delivering durable performance for seasonal trips and regular use.

• High-quality 3D-printed PETG construction for strength and flexibility
• Resistant to temperature-related degradation and everyday wear
• Smooth interior channel reduces splashing and guides flow efficiently

How easy is it to use and maintain?

Installation and removal are tool-free and take only seconds using the cam-lock release. The wide mouth makes rinsing and drying simple, and the PETG surface cleans easily after dusty campsites or municipal water fills.

• Tool-free cam lock collar for fast install and removal
• 4" opening accommodates large containers and hoses for quick fills
• Easy to rinse, inspect and store between uses

Who is this for: The Saillong 4" RV water inlet funnel is built for RV owners who want a reliable, hands-free way to fill their fresh water tanks without spills or adapters. It’s particularly useful for solo campers, those who frequently top off from jugs or high-flow hoses, and anyone upgrading from makeshift funnels to a durable, secure connector that fits 1¼" gravity inlets.