The Polar H9 is a reliable heart rate sensor with a black chest strap designed for precise fitness monitoring. This model features Bluetooth and ANT+ connectivity technologies, ensuring compatibility with a wide range of fitness apps and devices. The sensor operates with a CR2025 battery, allowing for approximately 400 hours of continuous use, which equates to about a year of daily one-hour training sessions. The transmitter unit measures 34 x 65 x 10 mm and is made from durable ABS plastic with stainless steel components for lasting performance. The included chest strap is made from a flexible blend of 38% polyamide, 29% polyurethane, 20% elastane, and 13% polyester, providing comfortable wear during various physical activities. This heart rate monitor is waterproof up to 30 meters, making it suitable for swimming and water-based exercises. It operates reliably in temperatures ranging from -10 °C to +50 °C, ensuring consistent performance in different environments and seasons. The Polar H9 is compatible with Polar Club systems for group heart rate display in fitness facilities and works with iOS devices from iPhone 5s (iOS 12 or newer) and Android devices with Bluetooth 4.0 capability (Android 6.0 or newer). The XS-S size chest strap adapts to various body types for secure positioning during movement. This sensor provides accurate heart rate data for fitness tracking, training optimization, and health monitoring applications.