The HydroKnit band is a sleek, fast-drying fabrication that’s a fan favorite for a reason. It dries twice as fast as SuperKnit and retains 30% less water – making it a must-have for water sports, high-sweat activities, or just taking a shower. 

The translucent battery is a WHOOP first and the perfect way to show off your new bands. You’ve got goals and so do we—like keeping you charged wherever your day takes you. Get continuous data for days on a single charge with our waterproof* battery pack that enables you to charge on the go while you wear it. 

To charge your WHOOP® 4.0, simply slide the battery pack on your device to charge on the go. Use the included USB cable to recharge your battery pack from a laptop. 

Includes 1 HydroKnit Band and 1 Battery.