With the launch of its latest fitness tracker, Whoop is ushering in a new era of wearables. The Whoop 4.0 ups the tech to capture the most accurate data with 5 LEDs and 4 photodiodes that monitor recovery, sleep, and training. In addition, it includes new biometric tracking to keep track of skin temperature and blood oxygen to deliver the most personalized feedback and coaching. It's smaller in size, and with a waterproof battery pack, you can continue to track 24/7, even during showers and swimming. The new model will also take wearables beyond the wrist with Whoop Body — a new line of smart apparel that features built-in pockets to hold a Whoop. The Whoop 4.0 comes free with a paid subscription.