This product is not waterproof. It is used by many as a panty liner, and we have an increasing number of repeat customers. Both sides are double gauze, with a three-layer construction that includes 100% cotton fabric in the middle. It can be washed and used repeatedly. It should fit comfortably in your underwear without any discomfort. We hope you enjoy it as a reversible product. Size: Length 17 cm, Width 7 cm Thank you for viewing.