Worn Once! Compatible with the Orangetheory Fitness app for use during in-studio, at-home and out-of-studio workouts. The OTbeat Burn measures distance, calories, and your unique heart rate data so you can get the most of your workout. It has a sleek, black band that can be worn on your forearm, or bicep. The box includes: OTbeat Burn heart rate monitor Two breathable black armbands in two sizes (S&M) Mini-USB Charging Cable