Compatible With: Intended only for use on newer Kenworth models that have fuel tanks which have a thermally vented Attention: The Diesel Fuel Cap is Non-Locking, Non-Vented and for diesel fuel tanks marked ULTRA LOW SULFUR DIESEL and LOW SULFUR DIESEL. This fuel cap is not vented, your fuel tank must be vented SIZE: This Non-Locking Fuel Cap inner diameter is 3.5" and out diameter is 4". Before order, please measure the diameter of your current fuel cap or fuel tank fill tube first OEM Quality: This Diesel Fuel Tank cap is real 100% aluminum casted, has a 6.5" chain and 6.5" bail which are made stainelss steel After-Sales Service: We sincerely appreciate the purchase of our 3 1/2" Diesel Fuel Cap For Kenworth Trucks. If you have any quality problems, we will reply to you within 24 hours wholeheartedly. We value your shopping experience Diesel Fuel Cap for Kenworth Trucks 3.5" Non-Locking, Non-Vented, for Low Sulfur labeled diesel fuel tanks