It didn't work... I had the hydra rester of American origin and much more expensive, and for 9 years I was carefree from the hydraulic shock that it causes in the hot water usage in the solar... at some point the anti-shock device "blew," and I tried the watts as a cheaper option... no... stay away... I paid for the hydraulic and product again and was calm once more... they have a lifespan these...

American made and sourced, you put it on, it does what it's supposed to do, and you no longer have to deal with it. It's a bit big. I deduct one star for what it says on its packaging about lead - I haven't found out what applies to us.