Compatible with WHOOP 4.0: Our wristband and Bicep bands are expertly designed to perfectly fit the WHOOP 4.0 sensor, ensuring a secure and seamless integration for optimal performance during your workouts. | FITCENT Wristband Bicep band is woven from high-quality recycled polyamide material,which can prevent skin from irritation rash, breathable, durable. Allowing sweat to escape, drying fast and easy to clean. | Adjustable Size: 24cm band compatible for your Wrist. 38cm is for your Bicep. And we include a complimentary U-shaped frame with your purchase. | Fashion Meets Functionality: Elevate your fitness gear with these stylish wrist and arm bands. Designed to be both functional and fashionable, they seamlessly blend into your everyday attire, making them a must-have addition to your collection. | Variety of Colors: Choose from a range of vibrant colors to match your personal style and wardrobe. Whether you’re at the gym or out on the town, these bands are the perfect accessory to elevate your outfit.