This listing is for a Pack of 5 This olive is made from brass which, whilst harder than their copper equivalent, can give greater mechanical strength by biting into the pipework through greater tightening force The copper alternative to this brass olive but can offer easier sealing capability due to them being softer but offer less mechanical strength Brass olives are ideal to use on chrome pipe as they bite into the hard chrome surface with greater force The use of PTFE tape is not necessary as the olive forms the seal and not the thread. The use of PTFE on the thread can restrict the ability of the olive to form a seal, Manufacturer: Cubralco