This was about 5 or 6 yrs. ago, and within the year I installed them they detected a leak at the hot water heater, and one in the central heat unit which had a crack. Thank God I had these installed, I shudder to think what would have happened.
I can't remember the brand, I know they were not expensive, under $10 each, got them at Home Depot. Most any will do the job, these cheap ones proved their worth.