This product is either discontinued or we cannot get that from suppliers.
JABRA Biz 2400 Ii Mono Biz 2400-2420 2403-820-205, Wired Headset, Noise cancelling, Uni-directional: Ø 30 x 6.4mm, Input power 20mW, Sensitivity NB - 10 dB Pa/V ±3dB/WB: 8 dB Pa/V ±3dB, Impedance NB: 300Ω ±15 %/1kHz/ 1.0V, WB: 300Ω ±15 %/1kHz/ 1.0V.
The Jabra Biz 2400 II 2403-820-205 is a Wired Monaural Headset with a QD connector and Noise Cancellation microphone. It enables the clearest conversation for closer connections with your caller.