Protect your new mattress or box spring with the Millano Bug Basics Mattress Encasement. Constructed of 100% Polyester, this breathable encasement is suitable for mattresses and box springs. The mattress encasement is durable, convenient and can fit mattresses and box springs from 6” to 10” deep. The zippered design encases your mattress completely protecting your investment and creating a barrier from bed bugs, mildew and dust mites. Keep your mattress clean and fresh with the Millano Bug Basics Mattress Encasement! 1 Mattress Encasement. Waterproof. Protects Against Bed Bugs and Dust Mites.