This is a thermal warmer with a polyester cover, approximately 22cm x 20cm in size. - Size: Approximately 22cm x 20cm - Material: 100% Polyester - Cover Material: 100% Polyester - Model Number: B0097011AB Thank you for looking. This was a gift, but I haven't had the opportunity to use it, so I'm offering it to someone who will. MUJI (Ryohin Keikaku)