I have a Kent RO last 5 years. It works well and have no complain about this product. Yes its catridge I change twice in a year, All its catridge and filter change depend upon water quality. We are staying in a coal belt so water is always mix with mud and impurities, so it catridge takes 1-2 year to change. all team of this company is supportive and help whenever u call them, In our area it’s distributer is a nice person always ready to help.if his electrician are absent he
himself come and solve problem. I am happy with Kent RO water purifier