3 newborn 5 one size Rumparooz Cloth Diaper Covers are designed to fit over most newborn fitted or prefold diapers. Covers may be used multiple times before washing but should be placed into the laundry if it becomes soiled. Kanga Care uses a water resistant polyester TPU which is a solvent-free polyester fabric that has been laminated with a thermoplastic polyurethane using a heat bonding process, not chemicals. This process is low in toxicity and is better for the natural environment than traditional PUL.