The Sennheiser SC 660 USB ANC Corded Headset is Sennheiser's USB premium USB corded headset with Active Noise Cancelling and Ultra Noise Cancelling microphone . Its designed to be used with your computer only - no further cables are required as this headset has a direct connect USB end. It is perfect for dictation programmes, webinars, video conferencing, listening to audio / video etc and obviously perfect for noisy offices. If you have a modern phone with a USB connection for a headset port then you can use this with your phone but ONLY if the headset port is USB. The Century series are Sennheiser's absolute best headsets - they've put their 70 years of expertise to good use on this one. Its really is the best sound you can get in a corded headset, with HD voice clarity, an ULTRA noise cancelling microphone but still lightweight and comfortable enough to wear all day. Modern collaborative office environments are becoming increasingly noisy and challenging our ability to concentrate. Active Noise Cancelling is essentially technology which 'hears' the noise around you and sends out tiny signals that you can't actually hear, to counter-act them. That's the simplified explanation, anyway - what it means for you is that you can get your work done in peace. If you need to keep an ear out on your colleagues, you can turn this function off. The ultra noise cancelling microphone means that the person you're speaking to won't hear anything but your dulcet tones. Great for dictation in a noisy office as Dragon (or other) won't get confused with the background noises - so this will minimise the error rate. Most of our headset team wear ultra noise cancelling headsets (albeit wireless) so call and ask for a little over the phone demo of just how much noise it blocks out.