ALS working as IT Consultant, WOW-what an excellent piece of hardware, allows me to use computer as before my disability, no need for any modifications to Windows OS. Never had to recalibrate. Allows great deal of head motion. Use it on several computers. Allows maximum independence. Use all kinds of software: web browsers, advanced software dev. tools, communication, Envoronmental control. Use magnifier a lot! Blink or dwell, plus amny other custom settings. I could not live without it. Best Eye Tracker out there, and I have tested several.