These cloths have a dual layer of copper fibres which will get rid of stubborn stains and dirt such as burnt on food and rust cleans extra thoroughly fine pure copper integrated with stronger fibres universal use for stainless steel glass ceramic and porcelain saucepans frying pans sink hob etc very long lasting rust free and rinseable size 15 x 13 x 02 cm material 75 pure copper 25 polypropylene