Perfectly compatible with Yealink PhonesRuns right out of box, a QD to RJ9 plug-and-play setup makes the connectivity toYealink IP phones. The phones can automatically optimizes acoustic parametersfor your YHS34/YHS34 Lite. Perfect match with Yealink desk phones give you optimized audio quality.Unparallel Audio ExperienceMade for calls, YHS34/YHS34 Lite is kitted out with a high signal-to-noise ratiospeaker and independent cavity design. The passive noise cancellation creates aricher and clearer conversations with reduced background noise. Ultra-lightweight, All Day Wearing ComfortBuilt for comfort with soft ear cushions and ultra-lightweight materials, the YHS34/YHS34 Lite is 10%