The Millie Short Crib Rail Protectors. The 2 rail Protectors measure 27 inches x 18 inches with 3 sets of ties. It has a soft terry cotton backing over a waterproof lining to create a moisture barrier to protect crib finish. They are made of 60% cotton and 40% polyester. Care instructions: machine wash warm, use only NON-chlorine bleach when needed, and tumble dry low.