The lifter works if you are away from the phone.
If you program it correctly in Communicator then you can use wireless headsets (some Plantronics models such as CS50/55/70, etc.) without the lifter. You need the RD-1 part from Plantronics to make the headset ring in your ear - but it is far cheaper and works better than the lifter. Some other models do not need the RD-1 or the lifter.
Once programmed in Communicator you simply use the same button on the headset ear piece to answer and hang up the call, the telephone takes care of the connection and disconnect rather than the lifter.
Steve