This high-tech monitor allows you to hear two children or two rooms at the same time. Like the iMonitor Vibe, it vibrates when your baby needs you, but it also has two colored sound lights to let you know which baby you're hearing at any given time. It uses the best-performing digital technology available, offering unbelievable clarity, privacy, and a range up to 2, 000 feet. Other handy features include: a parent unit locator, child unit battery back-up pack, and out-of-range alarm.