Infrared Finger Ear Clip Heart Rate Monitor USB Headphone Connector 3.5 mm Works with Smartphones, PC and Sports Equipment (Finger Clip) : Amazon.in: Electronics
Grove - Finger-clip Heart Rate Sensor with shell | Seeed Studio Wiki
Grove - Finger-clip Heart Rate Sensor | Seeed Studio Wiki
Grove Finger-clip Heart Rate Sensor w/ Shell - RobotShop