This is the heart of any good anti-bed bug protection system. While most box spring covers are made thinner and less heavy-duty, our SecureSleepΓäó Box Spring protection is stout and durable where you need it the most. The corners will not tear, and the bed bugs will not get through. Woven micro-polyester, with nano-urethane lining and reinforced seams. A must have for apartment renters. - 100% Micro-Polyester, Comfortable, Breathable Fabric - Patent Pending Zipper Technology - Entomologist Tested Effective - Machine Washable - Available in Twin, Twin XL, Full, Queen, King, and Cal King sizes Product Dimensions: 72in. X 84in. X 12in. Includes:1 Cal King Boxspring Encasement SecureSleepΓäó Box Spring Anti-Bedbug Encasement: California King Boxspring Encasement #851352002156 - Mattress Pads