The Watts LPSOV is the correct part that performs the following applications:
The Watts LPSOV Leak Detector and Shut-Off Valve detects leaks and shuts off water flow to your water drinking system should a leak occur. Also known as part number LPSOV, this water leak protection system is designed to help eliminate the possibility of damage to your property. When a leak occurs, an absorbent applicator tablet expands to close the valve and shut the incoming water supply off.
Watts LPSOV Leak Detector specifications:
Two applicator tablets are included with this Watts Leak Detector. Replacement application tablets are available and comes in a package of two. Be sure to keep the Watts Leak Protector Replacement Cartridges out of the reach of your children and pets. This LPSOV Leak Detector is ideal for under counter reverse osmosis and drinking systems.