CQtransceiver Office Corded Telephone Headset Boom Mic for Plantronics Phones Landline T20 T50 T100 Monaural over-the-head wearing style Telephone Headset for comfort and awareness of environment Direct connect over the head headset, no additional amplifiers or adapters required 2M coiled wire Flexible boom design allows to adjust mic freely RJ9 connector to replace telephone handset