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- IMPROVES RIDE – The Flex Air 5th wheel pin box combines our time-tested Air Ride technology with our Rota-Flex pivoting head to significantly reduce fore to aft movement and vertical tug-of-war between a 5th wheel RV and tow vehicle
- INNOVATIVE STRUCTURE – This pin box contains an internal air bag that moves in a scissor-like motion to absorb vibrations, a rubberized compound to soften jarring movement, and an oil shock absorber to handle rebound action, dampen kickback and control chucking
- SIMPLE INSTALLATION – The Flex Air is ready to be installed as soon as it comes out of the box. It uses the same bolts as the original pin box, so no additional hardware is needed for installation
- BUILT TO LAST – Constructed with steel and a black powder coat finish that protects against rust, this pin box is extremely long-lasting to ensure peaceful towing day after day
- SPECIALLY DESIGNED – The Flex Air is specifically configured to replace Lippert 1621 5th wheel pin boxes with a towing capacity of 18,000 lbs.
With the Flex Air® Pin Box by CURT®, you can stabilize your 5th wheel trailer or RV with ease. The Flex Air boasts an internal air bag and built-in strut that team up with a rubberized pivoting head to reduce chucking and virtually eliminate bounce and jarring. The pivoting head regulates movement of the king pin within the hitch while the rubber compound absorbs road shock, giving you a smooth ride that keeps things in control through harsh roads. Leave unwanted movement right at home!
The Flex Air uses innovative technology to ensure your towing experience is superior. It utilizes an internal air bag that moves in a scissor-like motion to absorb vibrations, a rubberized compound to soften jarring movement, and an oil shock absorber to handle rebound action, dampen kickback and control chucking. The Flex Air 5th wheel pin box combines our time-tested Air Ride™ technology with our Rota-Flex™ pivoting head to significantly reduce fore to aft movement and vertical tug-of-war between a 5th wheel RV and tow vehicle.
Towing 18,000 lbs. never felt so good! The Flex Air is designed to replace Lippert 1621 pin boxes and has an 18,000 lb. gross trailer weight (GTW). It comes ready to install and uses the same bolts as the original pin box, so it doesn’t require any additional hardware for installation. Constructed with high-strength steel and finished with a black powder coating, the Flex Air is the ultimate 5th wheel pin box to tackle your towing needs for the road ahead.
- Replaces Lippert 1621 5th wheel pin boxes
- Reduces chucking and absorbs road shock
- Long jaw with pivoting head
- Features Air Ride™ technology
- Bolt-on installation with no assembly required
- Constructed with steel and a black powder coat finish that protects against rust
- 18,000-lb. towing capacity
- Made in the USA
| Finish | Black powder coat |
|---|---|
| Material | Steel |
| Replaces | Lippert 1621 5th wheel pin boxes |
| Width (inches) | 21.5 |
| Height (inches) | 25 |
| Length (inches) | 44 |
| Physical weight (pounds) | 249 |
| Towing capacity (pounds) | 18000 |
| Dimensional weight (pounds) | 142.47 |
- What is the towing capacity of the curt l05 flex air pin box? The Curt L05 Flex Air Pin Box has a towing capacity of 18,000 lbs.
- Does the curt flex air pin box require any additional hardware for installation? No, the Flex Air Pin Box uses the same bolts as the original pin box and comes ready to install with no additional hardware required.
- What technology does the curt flex air pin box use to improve the ride? The Flex Air Pin Box combines Air Ride technology with a Rota-Flex pivoting head, an internal air bag, a rubberized compound, and an oil shock absorber to reduce movement and absorb vibrations for a smoother towing experience.
- Is the curt l05 flex air pin box compatible with lippert 1621 pin boxes? Yes, the Flex Air Pin Box is specifically designed to replace Lippert 1621 5th wheel pin boxes.
- What materials are used in the construction of the curt flex air pin box? The Flex Air Pin Box is constructed with high-strength steel and finished with a black powder coat that protects against rust and ensures durability.
Factory-Fresh OEM Parts — the same brands installed in new RVs straight from Elkhart. Genuine, name-brand components made to order — never generic, never outdated. Sourced directly from the original RV manufacturers for perfect fit and factory-level quality.