This is an aidlab v1, i bought for a project 5 years ago. Unfortunately it doesn’t fit me that well as I have moobs so I tend to use my watch for heart rate. They have their own app and a few other integrations. It was about 300 euro new. There is a v2 now which is on their website. Here’s an AI summary…

Aidlab v1 Heart Monitor (64MB) – Second Hand

This is a specialist wearable device designed for those who need accurate, clinical-grade ECG monitoring beyond what ordinary fitness trackers offer. With 64MB of onboard storage, Aidlab v1 can store up to 24 hours of detailed heart data—ideal for continuous monitoring without needing your phone nearby.

Key Features:
- 24-hour data collection: Record a full day of ECG, respiration, and health data on a single charge.
- Advanced sensors: Tracks heart rate, ECG, breathing, skin temperature, and movement.
- App integration: Syncs seamlessly with the official Aidlab app for real-time data visualization, history, and health trends.
- Open for developers: Access APIs and SDKs for custom integrations, home automation, and research projects.
- Reliable and precise: Trusted by health professionals and researchers for its accuracy and flexible data