We realized that a lot of people wish to protect their mattresses from bed bugs and dust mites but cannot unzip and remove mattress barrier covers I mean the mattresses are way too heavy to remove encasement and wash regularly. So we created this fitted sheet style of Mattress Barrier. This is easy to remove and wash often to keep critters from invading your bed. The barrier cloth is designed to block dust mite excretion animal dander and all sorts of household dust from passing between sleeper and mattress or pillow. It's the most tightly woven natural material we carry completely prevents airflow and can help with a lot of other airborne chemicals based on its very small pore size 4.5 microns. No urethane finishes on our barrier like many others have. We use our cotton covered elastic and make these to fit up to 8" mattresses. See our other offering for deeper mattresses.