This product is either discontinued or we cannot get that from suppliers.
Poly Plantronics Voyager 4210 212730-08, Up to 12 hours talk time and 15 hours listen time, Up to 13 days standby time, Blutooth 5.0 with BLE Bluetooth Profiles used: A2DP, AVRCP, HFP, HSP, Optimized for telecommunications, music/media, Speaker 20 Hz - 20 kHz, Speaker impedance 32 ohm, Speaker 32 mm, 360mAh typical/350mAh minimum.
Power up productivity for office workers with Voyager 4200 Office and UC Series Bluetooth® wireless headsets. Connecting is seamless—desk phone, smartphone or computer. Outstanding audio, freedom to roam.