Pulse Sensor is a well-designed plug-and-play heart-rate sensor compatible with Arduino.It can be used by students, artists, athletes, makers, and game mobile developers who want to easily incorporate live heartrate data into their projects.The sensor clips onto a fingertip or earlobe and plugs right into Arduino with some jumper cables.It also includes an open-source monitoring app that graphs your pulse in real time.Colour:blackredmaterial:ABS plasticPower: 3-5VFit compatible with:Arduino Raspberry piDiameter: 16mmMagnification: 330LED Wavelength: 609nmDimensions:L 220mm x Diameter 16 mmPackage Included1 x Pulse Heart Rate Sensor ModuleNote: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.