I have purchased a couple of Stage 8 shower filters from this company. To date 3 of the 4 plastic screw-on ends have split and rendered the filters useless. The fault, I believe, is in either the design or the quality of the materials used in the manufacture or in the quality control, period. I have contacted the company 3 times, twice I have been advised to purchase more ends more ends as replacements at my expense. The last time I spoke to a gentleman who proceeded to tell me that it was my fault because I was not replacing the cartridges often enough, thereby causing such a build up in water pressure that the caps failed. When I challenged him on this, given that I regularly cleaned the filters so that at no time did the water flow actually stop, I was told again that it was still my fault because I did not change the filters regularly enough. Oh really? In other words, to me,there is a fault with the product because it can't handle fluctuations in household water pressure, and will eventually break. I tend to agree with the person who left one of the other comments,not a good company to deal with and I don't know about their other products, but if they are manufactured by the same organisation that produces the Stage8 Shower Filter, they could also be rubbish. LET THE BUYER BEWARE!!!