Based on this product's specifications, here are some alternatives and similar models
Heart Rate Monitor Belt Coros HRM-LIM, chest HRM sensor, wearable cardio transmitter
Summary description:
Coros HRM-LIM is a chest-mounted heart rate monitor belt (HRM) designed to measure and transmit accurate heart rate data during exercise. The unit is a wearable sensor intended for continuous cardio monitoring, compatible with devices that accept standard HRM signals. Use cases include running, cycling, gym training and interval workouts where chest-based accuracy is preferred.