The ring cleaner from Petromax is a high-quality utensil made of stainless steel that gets to the heart of burnt-on food. Effortlessly clean your cast or wrought iron pot or pan - without damaging its valuable patina. The structure of the interlocking rings gently removes food residues and does not damage the surface of the cookware. Here's how it works: Allow the cookware to cool, soak in warm water for a short time if necessary, then gently rub off the burnt-on residue with the damp ring cleaner, rinse again, dry - done. You do not need washing-up liquid.