* All Natural * Function and material are paramount in the design of these covers. With a precise fit, you don't need a closure. Are you aware of your ecological footprint? Undyed wool felt can be returned to nature, it is 100% biodegradable. Our colors of unpainted wool felt are: Gray, sand brown (taupe) and black. These are mixed colors by a mixture of the three colors of wool, black, brown and white. Because, have you ever seen a gray sheep ?!