Our 210V has a 1" ID barb to threaded elbow, 1" threaded PVC ball valve and 3" rubber donut. I added a 3/4" garden hose adapter. Here's a picture minus the rubber donut (which we don't use):
I quickly searched on the internet and found something close from
cleandump:
Drip Proof Shut Off Valve, Model CDV1
You can buy everything for the stock setup except for the rubber donut at your local hardware store. However I think the threaded adapter that the clean dump version includes is a good idea, you'd have to purchase a 1" threaded to barb adapter to use it with your current hose.