hepa

Boundary seals that help keep a certain environment sealed in while keeping the world out are everywhere.

If you look around your home, you may be surprised to see there are seals surrounding every door — and not just at the bottom. Your oven, microwave, and of course refrigerator door all have seals around them.

All these seals are different, yet they perform the same function. Your microwave is especially interesting, as its primary purpose is to keep microwaves from escaping