Color: Gray Replacement sport loop band compatible with WHOOP 4.0 Fitness and Activity Tracker. Soft, braided nylon construction and an adjustable hook and loop fastener provide a comfortable, secure fit for daily activity. Key features and benefits Compatibility: Designed for WHOOP 4.0 Fitness and Activity Tracker. Comfortable material: Elastic braided nylon is soft, lightweight, and skin friendly for long wear. Breathable design: Woven construction allows airflow and lets sweat escape to reduce moisture and discomfort. Adjustable fit: Solo loop style with a sturdy hook and loop fastener adapts to a wide range of wrist sizes for a snug, secure fit. Stretchy and durable: Elastic weave stretches for comfort while maintaining shape for regular use. Easy to use: Simple to attach and remove for quick band changes. Practical uses Running and cycling: Breathable and secure during cardio sessions. Gym and fitness classes: Stretchy, snug fit stays in place during movement. Travel and everyday wear: Comfortable for long days and sleep tracking. Additional information Color: Gray Material: Elastic braided nylon Designed as a replacement band for WHOOP 4.0 Fitness and Activity Tracker. We aim to provide reliable products and responsive customer support. If you have any issues, please use the platform messaging to request assistance.