The MattresSkin® Mattress Encasement is the second skin for your mattress. The mattress encasement fully wraps around your mattress with a tight invisible zipper and sealed inner seams for complete protection. Provides a barrier against pet dander, bed bugs, dust mites, allergens, and fluids. Use a performance mattress protector on top for temperature regulation impact. Twin XL encasement fits mattresses up to 15" deep.