Generic Custom Zippered Pillowcase Cushion Case Cartoon Calvin And Hobbes Printed 18"*18"(Twin Sides) Material: Made of 100% Polyester Fabric. Durable heat-resistant non-woven fabric; non-slip neoprene rubber Soft and comfortable handing feeling , environmentally friendly Prevent water from splashing out of the shower stall Attachment: Has 12 holes to which rings attach Warm Note : Machine wash cold. Do not bleach or tumble dry