Hi #RekanEasyWare ... EasyWare Part#: EP000605 Sensors can be worn on the finger or earlobe, can be connected to Arduino via the Internet line. It also has an open-source app program, you can put your real-time heart rate is displayed with the plot. Essence is an integrated optical amplifier and heart rate sensor noise elimination circuit. Spesifications : - Supply voltage: 3V or 5V. - Power: 3-5V - Diameter: 16mm - Magnification: 330 - LED Wavelength: 609nm Package : - 1x pulse sensor pulse heart rate sensor for Arduino