Hammer Fitness Band Offer: Get upto 50% off on fitness bands from Hammer. Also, get an extra 10% coupon off. Fitness bands, also known as fitness trackers or activity trackers, are wearable devices designed to monitor and track various health and fitness-related metrics. These devices often have features like heart rate monitoring, step counting, sleep tracking, and other activity-related data. Some fitness bands also offer smartwatch-like capabilities, such as notifications for messages and calls.