Product review (1 stars): Caution! Flood hazard due to o-rings
I bought a single-handle valve and ended up using two $8 American Valve quarter-turn valves. Why?

The Watts Duo-Clozure and similar "single handle" valves seems like a good idea but are very risky. Why? O-rings. The Watts installation requires 4 O-rings. The repair kit has seven (7) o-rings and 4 Teflon disks. All of these o-rings are cheap neoprene, not even silicone.

So basically you have something like 11 o-rings between high pressure water and your house. How long until one blows out? It is scary to think about. Other brands may have less o-rings, but all single-handle valves have some.

Quarter-turn valves, even though made in China of course, are a well-proven and simple technology. They have very heavy bushings that are not going to just blow out suddenly and flood your house.

It only takes about 3 seconds more to turn off two valves. So consider buying a less than $30 Oatey or similar kit rather than the single handle valves.