The ComfortMark Mattress/Box Spring Encasement protects your mattress or box spring from pests. For a new mattress and box spring, it's important to protect your mattress. This encasement will seal the mattress and box spring to prevent pests making it into your new bed. Any pests already in the bed will die off because they will be deprived of their food source. The encasement is also an excellent way to protect from allergens because dust mites cannot enter through the barrier.