The Reusable Desiccant Plugs remove moisture from the combustion chamber and intake manifold. Simply remove spark plugs, thread in desiccant plugs, and store vehicle. Check plugs periodically, and when desiccant color changes from blue to pink, remove plug, empty desiccant material onto foil and heat in oven to dry out. Refill desiccant plug and install back into spark plug hole.