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 opti- mized audio quality. Unparallel Audio Experience Made for calls, YHS34/YHS34 Lite is kitted out with a high signal-to-noise ratio speaker and independent cavity design. The passive noise cancellation creates a richer and clearer conversations with reduced background noise. Ultra-lightweight, All Day Wearing Comfort Built for comfort with soft ear cushions and ultra-lightweight materials, the YHS34/ YHS34 Lite is 10%~30% lighter than other headsets in the same range. Its ergo- nomic design makes this headset comfortable enough for long conference calls and all day use. General Headset cable length: 0.9m QD to RJ9 cable length: 1.2m Color: Black Storage temperature: -30 C to +70 C Operating temperature: -10 C to +50 C Microphone Microphone type: Uni-Directional ECM Microphone frequency response range: 100 Hz-8 kHz Microphone bandwidth: Wideband Microphone Sensitivity: -44.0 dB re. 1 V/Pa Speaker Speaker size: 28mm Speaker sensitivity: 93 dB SPL @ 1 kHz Speaker Frequency response range: 20 Hz-20 kHz Speaker impedance: 32, @ 1.0 kHz Speaker input power: max 10 mW Speaker bandwidth: Wideband