Greenzone Sleep Terry Waterproof Bamboo Mattress Protector, California King Cotton Imported Material: Top - 56% bamboo rayon/24% cotton/20% polyester; Sides  100% polyester Bamboo protector is soft and repels and eliminates dust mites 100-percent waterproof and hypoallergenic Fitted sheet style, deep pocket fit Machine washable and dryable 20 year warranty