My Terminator gauge took a dump and I don't know the thread size. 20 miles to the hardware store, so hope to save time and gas. Texts to a few dealers have yielded zip. Two 1/8 npt gauges that are about an 1/8" different in thread diameter dont fit. It might be metric? M6 too small, maybe m7? If you KNOW the ANSWER, please respond. Thanks, Bill.