Here we have a Very nice ball valve. I am not sure if it is used or new old stock? Made by Rockwood, Model 1-1/2M-101. It also says 300 WOG AND 250 LPG. I assumed it was a water valve but It might be a gas valve? Overall length without the cap on measures 6.187" The male threads are 1.977" diameter, the female threads are 1.750" on the inside, but the threads are actually larger than that, this would be the actual inside diameter as I have no way to accurately measure the diameter of female threads. The one end has a nice brass cap with a rubber seal inside it.
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If in Michigan add 6% sales tax. Thanks!