Compatible Models: This replacement band is compatible with the Whoop 5.0 and Apple Watch 1/2/3/4/5/6/7/8/9/10, Apple Watch 49/46/45/44/42mm(series10) or Apple Watch 38/40/41/42mm(series3), hybrid band is compatible with Whoop and Apple Watch models, (not compatible with the WHOOP 4.0). Easy Replacement: Adjust the band length to your desired size, remove the old band, replace it with the new one, and secure it with the original U-shaped bracket. Available in sizes S (fits wrists 6.0-8.5 inches) and L (fits wrists 6.5-10 inches), it's suitable for both men and women. High-Quality Materials: This Whoop armband/ankle band is made of premium nylon, making it breathable, stretchy, adjustable, and comfortable. Perfect for daily sports activities or exercise. (Note: If your watch band accidentally gets wet, please allow it to air dry before wearing to avoid moisture-induced skin irritation.) Easy Care: Washable, durable, wear-resistant, and non-pill and non-fading. After-Sales Service - If you have any questions, please feel free to contact us and we will respond promptly.