Instant Smile Medium Deluxe is a quick and easy way to improve the look of your smile temporarily. It's convenient since can be done at home. Your smile makes a strong impression at work, school or social situations. This personal care product includes instructions for fitting it onto your teeth and how to care for them. Make sure to remove them before eating or sleeping. These Instant Smile medium deluxe upper natural shade veneers fits an average adult's mouth. This product is designed to enhance your appearance and for temporary use only. It is not designed to chew food and cannot be used as a "Denture". Do not Eat or Sleep while using this product. Outlined on the foldout (included in the package) are personal fitting instructions. They are easy to follow and take only a few minutes using hot water and can be done in the privacy of your home. This product is NOT a partial denture or a "DENTAL DEVICE" and is intended for temporary use only for aesthetic purposes only. Do NOT eat or sleep while using this product. It is difficult to determine the appropriate size of the Instant Smile teeth for a particular person's mouth. Based on the feedback from other buyers the SMALL size would typically fit a child’s mouth or a small adult's mouth. The MEDIUM is now labeled “One Size Fits All” and fits an average adult’s mouth. This is a general guideline and is not a guarantee. We are unable to accept returns on used Instant Smile teeth. Please inspect the teeth to determine if they will fit before use.