Thank you for viewing. This is a Polar heart rate monitor, a chest strap type. It has been used about twice and has minor scratches, but no major damage. Please understand that this is a used item before considering a purchase. - Brand: POLAR - Type: Heart Rate Monitor - Size: M-XXL (67-95cm) - App Compatibility: Polar Beat/Polar Flow - Measurement Method: ECG - Features: High-precision heart rate tracker Includes the main unit and strap only (no box or manual). This item will be listed until the Mercari Festival (until December 16th). Thank you for your understanding.