【Wide Compatibility】Yealink RJ9 headset direct connects landline telephone, widely compatible with multiple brands of desk VoIP phones, such as Yealink Desk Phones T2x/T3x/T4xG/T4xS/T4xU/T5x/VP/Teams MP/SFB MP/Teams T5/SFB T5, Poly VVX x01/x10/x50, SNOM D3xx/D7xx, and Grand stream GRP/GXP/GXV. *Please refer to Yealink Headset Compatibility List- h/t/t/p/s://support.yealink.com/en/portal/compatible | 【HD Voice】This YHS34 office phone headset is kitted out with wideband HD audio technology and passive noise cancellation that ensures a richer and clearer conversations, eliminates background noises as well. You can communicate with other people clearly, especially suitable for noisy work environments such as call centers. | 【111g Super Lightweight】The uni-body design call center headset is design with foam ear cushions for all-day comfortable wear, which is 10%~30% lighter than other professional headsets in the same range. | 【Quick-Disconnect】The QD-RJ9 cable provides an easy way to step away from the landline phones without disconnecting the call or even removing your headset. | 【Made for Calls】Smooth adjustable headband fits for different head sizes, 330° rotatable microphone boom enables you to put the mic arm on either side when no in use.