Yealink YHS34 Lite Dual Headset Wired Head-band Office/Call center Black93 dB, 32, 20 Hz 20 kHz, 10 mW, Black Perfectly compatible with Yealink Phones Runs right out of box, a QD to RJ9 plug and play setup makes the connectivity to Yealink IP phones. The phones can automatically optimizes acoustic parameters for your YHS34 YHS34 Lite. Perfect match with Yealink desk phones give you optimized audio quality. Unparallel Audio Experience Made for calls, YHS34 YHS34 Lite is kitted out with a high signal to noise ratio speaker