Premium 100% Waterproof Mattress Protector Twin Size,, 21'' Deep Pocket Warm Tips: Before using, please do inspect the TPU membrane for any damage. TPU membrane provides waterproof protection. If damaged, avoid using the product. For any issues, please reach out to us via Amazon customer support. Premium Fiber Surface - Not only soft and comfort, but also has cooling, skin-friendly and good wicking properties 100% Waterproof - Back of GOPOONY mattress protector is premium TPU, which not only againsts perspiration, bed wetting, liquids and stains, but also keeps breathable and noiseless 3D Air Fabric - More soft and comfortable than the ordinary fabric protective cover, also highly breathable, which makes your bed more comfortable 18" Deep Pocket - Fits all types of mattresses up to 21" and prevent the mattress from moving Customer Service - We are confident in our products and we offer a 30-day return/replacement service. Please contact our customer support when needed Twin (39 in x 75 in) - For frequent accidents, we advice you to buy 2 pieces or more, so you can change another one when wash one