4iiii Innovations H64 wearable technology 1.04" 1000h 64-86cm IP67

Heart Rate Sensor Chest Strap

The H303 heart rate monitor is a wearable sensor designed for athletes who want accurate cardiac data during training. It transmits simultaneously over ANT+ and Bluetooth to compatible apps and devices. The unit weighs 0.059 kilograms and includes a pre-installed CR2032 battery. It suits cyclists, runners and team-sport players who need reliable real-time feedback.

Upgrade From Optical Wrist Sensors

Chest-strap placement eliminates the motion artefacts and sweat interference that degrade wrist-based optical readings during high-intensity intervals. The new hardware and algorithms filter noise caused by movement and perspiration. The jump is worth it when interval precision dictates pacing decisions or when a coach requires clean ANT+ logs for post-session analysis. Optical wrist units remain adequate for steady-state zone checks.

Snap-On Module With Adjustable Strap

The sensor module clips onto the supplied elastic strap, which adjusts from 64 to 86 centimetres. Pairing is automatic once the strap contacts skin; the front LED flashes ten times to confirm connection. Common issues include a loose strap that breaks skin contact during vigorous movement and forgetting to wet the electrodes before cold-weather sessions. The module is IP67 rated for splashes and rain but not for swimming.