Peace of Mind: BABY waterproof undermats will provide excellent protection against fluids, urine, perspiration, allergens, dust mites, and bacteria. It is 100% waterproof, yet breathable, comfortable and noiseless. The mat is vinyl (PVC) free and safe to sensitive skins. Silky Smooth and Soft to the Touch: OYO BABY mattress undermat is covered by high quality cotton fiber and high absorbent bamboo fiber liner, which allow the mat to feel exceptionally smooth on the skin, even after repeated uses and washes. Breathable and noiseless Barrier: Unlike traditional waterproof mats that use vinyl (PVC) as barrier, OYO BABY undermats use a safer material called TPU. TPU is toxic free, noise free and totally breathable.