Brass Compression Fittings are used in plumbing, and copper tube fittings (Ferrule fitting), to join two tubes or thin-walled pipes together. In instances where two pipes made of dissimilar materials are to be joined (most commonly PVC and copper), the fittings will be made of one or more compatible materials appropriate for the connection. Compression fittings are also used extensively for hot and cold-water faucets (taps) also, the fittings allow easy disconnection and reconnection. They are used due to their ability to provide leak-tight seals. These fittings can be remade.