The Whoop 4.0 Fitness Tracker with Superknit Band in Onyx is a versatile activity tracker suitable for both men and women. With its sleek black design and durable Superknit band, this fitness tracker is perfect for indoor and outdoor activities, especially for running and jogging. Powered by batteries, the Whoop 4.0 model provides accurate tracking and monitoring for your fitness goals. Plus, with free shipping included, it's a convenient and reliable choice for anyone looking to enhance their workout routine.