A crisping sleeve is intended for use in a microwave oven to crisp and brown food items placed within it.
Crisping sleeves consist generally of paperboard affixed with a susceptor that absorbs microwaves and converts them to heat. The purpose of the susceptor is to apply additional heat to a specific portion of the food, browning it. The paperboard is also often used as a rigid container to support the food items within.[1]
They are generally intended for a single use.[2]