Pulse Sensor is a well-designed plug-and-play heart-rate sensor for . 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 with some . It also includes an open-source monitoring app that graphs your pulse in real time. Colour:black&red material:ABS plastic Power: 3-5V Fit for: Diameter: 16mm Magnification: 330 LED Wavelength: 609nm Dimensions:L 220mm x Diameter 16 mm Package Contents: 1 x Pulse Heart Rate Sensor Module Only the above package content, other products are not included. Note: Light 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.