POLY Sync 20+ USB-A Speakerphone. Device type: Mobile phone/PC, Signal-to-Noise Ratio (SNR): 55 dB, Cable length: 28.1" (0.715 m). Driver type: Dynamic. Microphone frequency: 100 - 6700 Hz, Microphone direction type: Bidirectional microphone, Microphone sensitivity: -42 dB. Connectivity technology: Wired & Wireless, Interface: USB/Bluetooth, Bluetooth profiles: A2DP, AVRCP, HFP, HSP. Power source type: Battery, Battery technology: Lithium-Ion (Li-Ion), Talk time: 20 h