Review on Compatible Rainsoft UF 50T Filter CFS by Eric Young

I bought these filters thinking they would replace my Rainsoft Ultrafiner II summer carbon filters before and after cleaning but I was wrong . They won't fit, old filters have a nipple with 2 o-rings that go into the filter housing. I tried them out thinking they might seal the top of the case but no luck, the water coming out of the filter faucet splashed and sprayed water and air for five minutes until I gave up and put the old ones back in place. It would be helpful to better explain which Rain-Soft systems they are suitable for.