I can’t say about the quality of the product as all are almost same to me. But one thing that I must say, that is its service. Zero B’s service is worst. The worst ever service I have ever experienced in my life. It has been more than two weeks now and i am not getting my purifier’s service done. This is the time when we need water in these hot days. I don’t think from next month i even need it. I suggest everyone not to buy it at all.