OvisLink Single Ear Call Center Headset model OVHS-SOOM5-25 comes with a 2.5mm Quick Disconnect cord. It is designed to be directly connected to Cisco SPA Series Small Business IP Phone and desktop phones with 2.5mm headset jack. No amplifier is needed. 

Headset volume can be controlled by the volume buttons on the phone's keypad. To activate or deactivate the headset connected with the phone, simply press the headset button on the telephone keypad. This OvisLink Call Center headset services with solid, crystal clear voice quality.