Review on 6 Inch Dually Valve Stem Extenders - 2 Pack: Heavy Duty, Easy Installation for RV Tires, Truck, Motorhome, and More! by Jamil Fog

For reference, you cannot install these valve stem extensions on existing valve stems that already have a needle valve installed. You need to remove the needle valve on the existing valve stem and then attach these extensions which have their own needle valve. For my application (Sprinter 3500 RV with twin wheels) it would be necessary to remove the outer wheel by removing the valve stem from the inner wheel. wheel and then attaching these extensions. The reason I bought them in the first place is because I couldn't access the valve stem on the inner wheel without taking my RV to a tire shop. I bought 4" extensions from another seller for my outer wheels that I could fit over my existing valve stem, but I don't know if there are 6" extensions that work the same way.