This Peartune tuning kit removes the 16mph speed limit, allowing the motor to help you at higher speeds. For these Shimano bikes, the speed limit is raised to 31mph. Real speed will be displayed up to 14-15mph, at higher speeds the bike will show incorrect, slower than real speeds. The tuning kit can be activated directly on your bike's display. After pressing the 'LIGHT' button, from now on you will be able to ride at a speed of 25 mph and even up to 31 mph! To deactivate the tuning kit, press the 'LIGHT' button again. Your e-bike will then work the same as before installation of the chip. If the Light button is not activated on your ebike, do not connect red cable, and tuning kit will be activated when you will turn on the ebike. This Peartune tuning kit is made to fit all Shimano EP8 motors, with all Shimano displays made for EP8 motors. Legal Note. Please note that the operation of this type of modified electric bikes on public roads may be against the law in some countries. The manufacturer takes no responsibility for damages resulting from the use of Peartune products. Electric bikes equipped with Peartune products are not allowed to be used on public roads, cycling paths and public places. Electric bikes equipped with Peartune products can be used exclusively on private property and entirely at one's own risk. The use of Peartune products may void the warranty of your ebike. We strongly recommend using other safety features and protective gear to prevent injuries in higher speeds. Peartune products are thoroughly tested and we stand by their quality - Peartune provides 2 years warranty to all their products.