ask them for certification from an independent testing agency and the results of the test. it has been a issue for a long time and we have had no luck in getting information from any sales agent of magnets for proof that they work. we do know that to soften water you must remove the hardness from the water. common sense says any device that dosn't come in contact with the water and is bolted on the outside of the piping how can it remove calcium or hardness from water. I have asked and have never recieved an answer nor has anyone provided and scientific evidence that magnets work. we have been asking since the late 80's. i have personally tested water before and after a magnet installation and the water tests the same. hard before, hard after.