These Chrome Locking Fuel Caps for Kenworth Trucks are made with pride by Fuel Tank Accessories right here in America! The cap assembly is 3.5”-5.5 NS with an internal diameter of 3.375”. It’s best to double check your filler neck to ensure this is the correct size. The fuel cap is solid, so your fuel tank must be vented. This comes with an 8” chain & 6.5” bail and has “ULTRA LOW SULFUR DIESEL FUEL” printed on it. The ID under the cap is FTA-442L. The caps are sold as singles with two keys. Aluminum versions are available if you search for FTA-C-442L