Susceptors built into packaging create high temperatures in a microwave oven. ... A "crisping sleeve" is a device made of paperboard and affixed with a susceptor used both as a rigid container to support the food items within and to focus heat on the foodstuff. They are generally intended for a single use.

How does the Hot Pocket crisping sleeve work?

The Little Sleeve Is Called a Susceptor

Every Hot Pocket needs to be microwaved inside a little cardboard sleeve that's called a susceptor. The purpose of it is to absorb microwaves and concentrate more heat onto the Hot Pocket — in a sense “broiling” it so the crust becomes crispier.

Can you put crisping sleeve in oven?

Do not use crisping sleeve in oven. ... *Ovens vary; cooking time may need to be adjusted. Keep frozen. Cook thoroughly.