Compatible Models Designed specifically for Whoop 4.0 and Whoop 3.0 fitness trackers. Please note: fitness tracker device is not included. Quick and Secure Installation Easily attach or remove the band without tools. Align the connection points and press to lock securely onto your Whoop 4.0 tracker. The precise fit helps prevent the tracker and strap from becoming loose or falling off during use. Adjustable Fit for Comfort and Style Features a sturdy hookandloop fastener, allowing you to adjust the band for a firm, custom fit. Suitable for wrist sizes from 5.9 inches to 8.26 inches (150mm to 210mm). The sleek silicone design offers a modern look, suitable for both men and women. Makes a thoughtful gift for family or friends on birthdays, Christmas, Valentine's Day, Thanksgiving, or other special occasions. Soft, Breathable, and Durable Crafted from ultrasoft silicone that is skinfriendly, flexible, sweatresistant, waterproof, breathable, and lightweight. The metal buckle adds a secure feel with a smooth, comfortable touch. This design prevents skin irritation, making it ideal for prolonged wear. Versatile for Any Activity for everyday wear, workouts, outdoor adventures, vacations, sports activities, sleep, or casual outings. The combination of comfort, durability, and secure fit ensures your Whoop tracker stays in place and performs reliably in any environment.