It is 3 layers, upside and downside is modified PVC, core layer is high foam polymer. ... insulation,acid-resistant, alkali-resistant,erode-resistan, toughness and hardness, leaking proof and fireproofing....thinkness: 2mm,2.5mm,3mm,4mm,5mmwidth: 1 ... --green,blue,terra-cotta, yellow,white,red......double color: up and down is different UPVC 3 layers corrugated heat insulation sheet