Heat resistant surface outside, two layers of non-stick coating inside, freely combine, nice look. 18x9cm,20x9.5cm,22x10cm The non-stick coating we use is AKZO NOBEL from USA, we also use coating from South Korea, we have got FDA, LFGB certificates on health. The product is heat resistant surface outside, two layers of non-stick coatings inside, nice look, freely combine, easy to clean, the ...