Sennheiser 504575 PRESENCE Earset - Mono - Black - Wireless - Bluetooth - 82 ft - 100 Hz - 15 kHz - Over-the-ear - Monaural - Outer-ear (Sennheiser504575 ) Sennheiser 504575 PRESENCE Earset - Mono - Black - Wireless - Bluetooth - 82 ft - 100 Hz - 15 kHz - Over-the-ear - Monaural - Outer-ear