Bests & Worsts Reviews from Amazon

I am a plumbing contractor. I repair a lot of toilets due to bleach tablets and other bleach based toilet cleaners that treat the water in the tank. the bleach deteriorates the rubber seals in the tank. this product bypasses the tank and delivers the treated water to the bowl. I put these in 3 of my toilets. it keeps that hard to clean ring away and seems to last 4-6 months depending on the use. I was most impressed with how well it worked on the toilet in my workshop that is neglected most of the time. great product. I thought Amazon would have the best price on these, but my local Publix had the refills for $3.99. the kit was $5.99.