Replacement Chest Strap Material and build: Crafted from silicone, this breathable chest strap offers durability and enhances electrode transmission for accurate heart rate tracking. Comfort and performance: The stretchable silicone fiber blend adapts to body movements while keeping sensors firmly positioned, supporting reliable performance during training or gym sessions. Compatibility and sizing: Replacement Chest Strap is suitable for various models and features adjustable sizing from 27.56 to 39.37 inches for a secure fit during workouts. Target users and benefits: Designed for athletes, fitness enthusiasts, and outdoor adventurers who require a stable heart rate reading across activities such as running, cycling, and intensity training. Use scenarios: Running workouts needing steady heart rate data Cycling sessions with reliable sensor alignment intensity training and interval sessions requiring stable heart rate tracking