Samay - Zippered Waterproof & Bed Bug Proof Box Spring Encasement Cover - Twin Size 38 x 75 Inches Microfiber 100% Bed Bug Proof. 100% Waterproof. Includes: Box Spring Encasement cover only. Mattress encasement is sold separately. Protects the Box Springs on all 6-sides against allergens, dust mites, bed bugs, bacteria, fluids, perspiration and urine. SAMAY is a registered trademark and best-seller of Bedding Products.