Shop name:Chong Qing Shuo Yue Ke Ji You Xian Gong Si Sensor is a -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 graphs your in real time. Colour:black&red material:ABS plastic : 3-5V Fit for: Diameter: 16mm Magnification: 330 LED Wavelength: 609nm Dimensions:L 220mm x Diameter 16 mm Package Contents: 1 x Heart Rate Sensor Module Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.