Headsets available for most Vodavi phone systems.
Depending on the make and model of phone system, they all utilize a different adapter.
Most phone systems require some bit of programming to make the headset work. Some phone systems require a technician visit and other phone systems can be programmed by the end user.
Most Vodavi later model Phones require a 2.5MM headset jack to connect a headset to a Vodavi Phone.
Most Vodavi Phone systems require phone system programming to enable headset operation.