The WHOOP 4.0 Strap is designed with a strong focus on comfort, durability, and secure all-day wear, using a smooth woven textile that feels soft against the skin while maintaining excellent resistance to stretching and fraying. The strap features a streamlined adjustable system paired with a low-profile metal clasp that locks firmly in place without adding bulk, ensuring the sensor stays correctly positioned during workouts, sleep, and daily movement. Its breathable fabric construction helps manage moisture and sweat, making it suitable for continuous wear across intense training sessions and rest periods alike. Finished with subtle branding and clean stitching, the strap balances a minimal aesthetic with practical performance, allowing easy swapping between colors and materials while preserving the snug, flush fit that defines the WHOOP 4.0 experience.