Monaural IP headset for desk phones Wideband balance for Openstage phones 3-in-1 wearing styles: headband, neckband, ear hook Complete broadband audio Noise-cancelling microphone filters background noise HD voice for crystal-clear conversations Break-proof, 360° rotating microphone boom (FreeSpin) Luxurious ear cushions and additional cushioning on headband A connection cable or amplifier is needed to connect the headset (both options sold separately). Please note that the required connectioncable varies by phone. We are happy to help you find the correct cable. No additional cable is required when you choose to connect your headset via an amplifier.