Very useful bit of kitchen kit.
The mat is very thin and has to be used with a baking tray under to support it. It fits even large pans and if you want to use it in smaller trays, buy several (they are cheap enough!)and cut to size.
Dishwasher-proof, but it's difficult to see how you could lay it flat in one, so handwash and pat dry. Can be stored rolled up and doesn't kink when you come to use it again.
Can also be used to line cake storage tins or as a worktop protector but NOT as a chopping board!