Du-Bro Kwik Fill Fueling Valve (Glo) Part No: 334. The clean, safe way to fill your tank without disconnecting your fuel line from the carburetor. Perfect for models with enclosed engines. Easy to install. Comes complete with fueling probe. (Silver model is for GLO FUEL ONLY). Recommended fuel tubing size is Du-Bro Medium (3/32" ID) Silicone (Glo).