The wireless CS500-series Poly Headset CS540 (CS540A) is perfect for working in the office thanks to its large range. Other features: Monaural DECT headset for desk phones Three different wearing styles: Headband, ear hook and neckband Noise-cancelling microphone filters background noise Digital Signal Processing (DSP) for natural audio Choice of wideband or narrowband mode Wideband audio with CAT-iq technology SoundGuard DIGITAL protects you from sudden loud noises and limits the average noise exposure to 85 dBA Talk time: up to 9 hours Range: up to 120 m Weight: 22 g Includes: Headset, base station, headband, ear hook not included: Neckband Calls can be answered/ended through the headset: mechanical HL10 handset lifter or manufacturer-specific Electronic Hookswitch (EHS) module required (sold separately). Please inform us of your phone model so that we can find the compatible EHS cable.