Twin Mattress Cover - 20 Pack - These covers are manufactured with a sturdy 2 mil thickness of polyethylene. The material is puncture-resistant, ensuring reliable protection against dust, dirt, and minor impacts. Each plastic bag is tailored for twin mattresses, measuring 40 inches x 12 inches x 86 inches. A case of 20 covers will effectively protect 10 beds, including both the mattress and box spring.