Note-Professional installation is highly recommended if you have any difficult in installation! We have suggest many people go to the local professional repair store, they solve many problem during installation, and save vaule time, but DIY is also interesting, enough patience! If you meet any problem, please contact us! We will ty our best to help you! -The sensor is fixed at the position where the front wheel can be fixed, and the magnet is attached to the brake disc diagonally,-If you can't read the data, try the other side of the magnet.Feature-All in one motorcycle speedometer mph black, speedometer/tachometer/odometer, multifunction Indicator light-Waterproof, shockproof, anti-lightning, resistance to high pressure, with anti -UV & Anti-glare LCD screen, you can see very clearly in the eveningSpecifications-Diameter: 3.7 inches/ 95 mm-Packing size: 4.3 x 4.3 x 4.3 inches/ 11 x 11 x 11 cm-Shipping Weight: 0.9 pounds/ 0.4 kg-Packing including 1 x digital motorcycle speedometer, 1 x sensor, 2 x magnetic steel, 1 x meter bracket, 1 x speedometer sensor bracket, 1x Installation InstructionsInstallation Note-The default is 1 cylinder, if you set to 2 or 4 cylinder,it can not be changed to 1cylinder !!!!-The rpm could not work if your motorcycle is "Kawasaki" and "Regal Raptor" with Electronic injection engine.