• Product Type: Wired Headset • Headset cable length: 0.9m • QD to RJ9 cable length: 1.2m • Colour: Black and silver • Weight: 124g • Operating temperature: -10 °C to +50 °C • Microphone frequency response range: 100 Hz-7 kHz • Microphone bandwidth: Wideband • Microphone Sensitivity: -44.0 dB re. 1 V/Pa • Speaker sensitivity: 93 dB SPL @ 1 kHz, 60 mV • Speaker Frequency response range: 20 Hz-20 kHz • Speaker impedance: 32+/-4.8?, @ 1.0 kHz • Speaker input power: normal 5 mW, max 10 mW • Speaker bandwidth: Wideband • Compatible Yealink IP Phones: T19(P)E2/T21(P)E2/T23P/ T23G/T27G/T29G/T30/T30P/T31/T31P/T31G/T33P/T33G/T40P/T40G/T41S/ T42S/T46S/T48S/T42U/T43U/T46U/T48U/T53/T53W/T54W/T57W/T58A/ VP59/T41S SFB/T42S SFB/T46S SFB/T48S SFB/T55A SFB/T56A SFB/T58A SFB/MP56