The new Fitbit Charge 4 Fitness Activity Tracker in black is a unisex heart rate monitor designed for both indoor and outdoor activities. With a battery life of up to 5 days, this activity tracker by Fitbit offers features such as Bluetooth connectivity, exercise log, pedometer, calorie monitor, and a variety of other measurements. Suitable for running and jogging, the Charge 4 is a reliable companion for fitness enthusiasts looking to track their progress and monitor their heart rate in real-time.