Binaural IP headset for desk phones Complete broadband audio Wideband balance for Openstage phones 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 connection cable 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.