Made with soft-touch silicone, SportFlex is waterproof, sweatproof, and dirtproof-built to take on high performance and water activities. Includes a Band, Hook, Clasp, and a Fast Link(TM) slider that makes swapping bands easier than ever. Compatible with WHOOP Life-membership not included DESIGN: BUILT FOR HIGH PERFORMANCE: SportFlex is designed with waterproof, sweatproof, and dirtproof silicone. It's highly durable and designed to withstand your most intense workouts and adventures MADE WITH SOFT-TOUCH SILICONE: SportFlex is ultra-smooth, hygienic, and easy to clean. Small scuffs can be wiped off, or you can deep-clean the band with isopropyl alcohol and a lint-free cloth followed by a water rinse ADJUSTABLE AND BREATHABLE: SportFlex is made with an adjustable closure system to ensure a snug, secure fit-no matter how intense your workout. The band includes ventilation details, making it extra breathable and comfortable 100% WATERPROOF: SportFlex is completely waterproof, making it an essential accessory for everything from swimming laps and surfing to high-sweat, high-intensity workouts OPTION FOR ECG COMPATIBILITY: With a WHOOP Life membership, choose a SportFlex band to take on-demand ECG readings* ADDITIONAL DETAILS: *ECG: This feature is not intended for users with known arrhythmias other than AFib or users under 22 years old. It is not recommended for users with a cardiac pacemaker, ICDs or other implanted electronic devices. This is a medically regulated feature and is not currently available in every region. Find out if it's supported in your region here.