The miCoach Pacer – a small, lightweight device that delivers real-time audible coaching as you exercise via headphones or combined with your own MP3 player. During your run, the miCoach Pacer verbally coaches you (i.e. speed up to green zone, slow down to blue zone, etc), to ensure that you are staying within your targeted heart rate zone and keep you running at the right personal level.
Source: Adidas the official outfitter of the 2011 Dubai Marathon