Introducing the WHOOP 4.0 Health and Fitness Tracker with Battery Pack WS40. This activity tracker by Whoop is the perfect device for people who are always on the move. The device has a battery life of up to 7 days, making it perfect for long trips and outdoor activities. The device comes in a sleek black color and has a body area of the wrist. It's designed to track your running and jogging activities and comes with a Whoop Superknit model. The WHOOP 4.0 Health and Fitness Tracker with Battery Pack WS40 is the perfect device for people who are looking to stay fit and healthy. It's an excellent way to keep track of your fitness goals and monitor your progress. The device is new and sealed in a box, making it an excellent gift for your fitness enthusiast friends and family members.