How to use: Simply place the measuring wheel on the surface you want to measure and roll it along the path. The wheel will record the distance for you. Note that this item is for local pickup only at the MSU Surplus Store. Maintenance: Since it's a used item, you may want to clean it regularly. Check the wheel's spinning mechanism from time to time to ensure it works smoothly. If you notice any abnormal wear, it might be a good idea to consult a professional. And always keep it in a dry place to prevent rust and damage.