Dust mites are tiny creatures, typically around 250-300 micrometers in length. By comparison, a single grain of beach sand can be more than 800 micrometers! Humans react to the proteins in the dust mite allergen (approximately 10 microns in size), made up of decomposed mite bodies and their feces. Because of the microscopic size of dust mites and their allergen, the technology used to develop and manufacture zippered "allergen proof" or "mite-proof" encasings can be complicated. However, the process by which they make users feel better is fairly simple.

By encasing your bedding in a zippered encasement the dust mites that are inside your pillow, mattress and duvet are trapped. Blocked from their constant food source (your shed, dead skin cells), they eventually die. In the meantime, any mite allergen is completely blocked by the encasing from getting into the air you and your family breathe. It should be noted that because zippered enclosures are not a tight enough seal to completely prevent the escape of mite allergens, Zip and Block™’s anti allergen bedding are the only encasings that offer a protective flap in the front and back of the zipper to prevent allergens from escaping.