This is easy to use and seemingly accurate. A bit of an off taste to me, but that is common among these units with a flexible stem.
POLAR H10 HR Sensor: Bluetooth Enabled, 🏋️ Black, M-XXL – Advanced Accuracy for Heart Rate Monitoring
39 Review
Smart bracelet Xiaomi Mi Smart Band 5 RU, black
148 Review
Track Your Oxygen Levels And Heart Rate With IProven Fingertip Pulse Oximeter – Includes Battery, Case, And Lanyard In Blue
49 Review
SadoTech Necklace: A Wireless Medical Alert System For Caregivers And Seniors
44 Review