Thank you for viewing this item from among many others. This is the New Balance N5 Heart Rate Monitor unit. I purchased it a long time ago and confirmed it powered on when I bought it, but it has been stored at home without being used for a long time since then. I'm selling it to someone who needs it because I don't use it. The outer box is torn, and I haven't checked if it powers on since I turned it on when I bought it, and it currently doesn't turn on. It's probably just a dead battery according to the manual, but I'm listing it as a junk item. Please understand that this is a junk item. I cannot accept any complaints, returns, or refunds after purchase, so please check the images carefully before considering a purchase. The N5 heart rate monitor records heart rate and can manage up to 30 workout sessions. - Brand: New Balance - Model Name: N5 - Function: Heart Rate Monitor - Number of Sessions Recordable: Up to 30 sessions - Training Management: Workout management function - Supported Data: Calories, heart rate, exercise time, distance