This is a great tool for its price. This Bike Computer Odometer Speedometer has many useful functions. * It is also very durable considering even you have put over 500 miles on it, you even don"t have to change the battery. * It is functioned as tracking your training progress in real time. * Easy operation and durability make it popular with people. * Metarial: engineering plastics, electronic parts and components, and LCD display screen.