This I the third time I've bought one of these cloths. A few years ago, we installed "low-e" windows in our home, and were instructed not to use ammonia products to clean them. I purchased one of these cloths, and now I use only a spray bottle of water and an E-Cloth to clean them. I get a streak free finish, which I haven't been able to get with paper towel or newspaper. They also work great on our mirrors and appliances.