NWT Twin XL SureGuard Box Spring Encasement College Dorm Bed Mattress Protector 100% Waterproof – Six-sided premium protection against everyday liquids and stains; 10-year quality guarantee. Bed Bug Proof – Super fine zipper with Invisi-Zip and SureSeal technology completely seals off the box spring from bed bugs – use with a SureGuard Mattress Encasement. Hypoallergenic – Keeps Your Box Spring Clean & Fresh – Blocks dust mites, mold, mildew, pollen and pet dander on all sides. Soft & Noiseless – Smooth stretch-knit polyester surface hugs to your box-spring like a glove – Free from Vinyl, PVC, Phthalates, fire retardants and other toxic chemicals. Twin XL (39 in x 80 in) – Fits 8 to 11 inches deep; Zippered Box Spring Cover – Machine wash and dry. Independently lab tested and GREENGUARD Gold certified. I’m moving and it’s all gotta go! Smoke and pet free home