When we refer to “dust proof” watches, we mean watches that are not designed to be water resistant or water proof. A good way to tell this is if you do not see the word water anywhere on the face or case of the watch. This means the watch is not meant to get wet, so take care, even when washing your hands to not accidentally splash the watch with water. In order for the watch to remain dust proof, the crown (the knob used to change the time) must remain closed/pushed flush against the case unless you are changing the time. Even if you are not using it frequently, it is highly advised that you do not leave it pulled out. If you leave it pulled out, dust and moisture may get inside causing damage to the movement. This can also cause the oils inside to dry out, causing gear damage. If you would like to clean your watch, it is recommended that you use a soft cloth to brush the case as needed. Also, when you have the battery changed, it is a good idea for the gasket on the back of the watch to be checked to make sure it has not begun to age or deteriorate. If it is in need of changing, it is best to do so, as this will also help protect the inside of the watch.