Using the Makita 781007 - 2 spanner wrench is easy. First, find the right place on your Makita 4 - inch disc grinder or sander/grinder where you need to lock the grinding wheel or sanding disc. Then, insert the wrench and turn it firmly to secure the disc in place. When using it, make sure you apply the right amount of force. Too little and the disc won't be locked properly; too much might damage the tool. After each use, wipe the wrench clean with a dry cloth to remove any dust or debris. Store it in a dry place to prevent rust. This will help keep your wrench in good condition for a long time.