Zen Bamboo's Zippered Bamboo Mattress Encasement offers protection against damaging liquids, perspiration, and urine. Count on superior waterproof protection with this product! Using breathable material that allows for increased airflow, the ultra-cooling technology will keep you comfortable and cool throughout the night! Zen Bamboo's Bamboo Mattress Escasement can fit mattresses up to a full 18” tall. Every cover is OEKO-TEX Certified and free and clear of pvc, vinyl, and phthalates. Incredible quality at a more incredible price!