PLEASE MEASURE THE DIAMETER OF YOUR FUEL TANK FILL TUBE PRIOR TO ORDERING! One 3” diameter, 8 UNNS, non-vented, locking aluminum diesel fuel cap. Fits Volvo VNL ultra low sulfur labeled or PNG tanks 2010 & later. Cap is not vented, fuel tank must be vented, for low sulfur diesel applications only. Supplied with 2 matching keys (keys are not available separately) Includes rubber gasket seal, safety chain, and bail Approximate dimensions = Across threads cap 3”