Protect either mattress or box spring. Aller-Zip mattress and box spring encasements provide an effective barrier to infestation. Because treatments cant reach the core of an already infected mattress and box spring, they usually need to be disposed of - but no longer. Aller-Zip protects your mattress investment and most importantly, your health. Its smooth fabric toplayer is soft and comfortable under your sheets. Protects against leaks or tears for 10 years or the factory will replace at no cost.