About a year ago I picked up a 1998 Volvo A40 articulated hauler. Today I went to move it and found one of the tires a little low. When I went to air it up I found that the valve stem is larger than all my other equipment. Searching the net I find information about large bore, super large bore, z-bore, and Mega, but the sizes don't match. There is nothing in the service manual. The valve stem on this truck has a diameter of 0.475" or 12mm. Can someone recommend the correct Inflation gauge?