The Body Maxx Waist Trainer Extension guarantees that your trainer will fit around your waist with limitations. The 100% size guarantee will guarantee that the waist trainer you order will fit when you attach the 2.5” waist trainer extension. The extension will increase your waist trainer up one full size (for example if you ordered a size Larger the extension will convert your waist trainer to a size XL). The extension does NOT guarantee that the trainer would fit your body if you purchased a waist trainer that is more than 2 sizes too small. The size guarantee does not cover you if you purchased a waist trainer that is too big. As the waist trainer extension can only extend the product sizing, not reduce product sizing. Thus, it is still important that you MEASURE your waist before you place your order to ensure you will not be ordering a product that is too large or more than 1 size too small. If the extension does extend your waist trainer to a size that would fit you comfortably, you may purchase an additional extension for $14.99 to increase your waist trainer an additional 2.5” inches. Two waist trainer extensions are the maximum number of extensions that we recommend adding to your waist trainer. If you purchased a waist trainer that is too big for you, if you require a waist trainer that is two sizes larger than your originally purchased size, or you prefer not to use the waist trainer extensions you may pay the $14.99 restocking fee + shipping to exchange your waist trainer for any size of your choice. All sales are final on all waist trainer extensions – no exchanges, refunds, or store credit on waist trainer extensions.Please reach out to firstname.lastname@example.org to begin your exchange process. Our exchange conditions apply to products that do not fall within the 100% size guarantee.