Please always double check your filter size in your existing product and insure that your order is of correct size match NW is not responsible for wrong size filter orders and due to health issues filters can not be returned. In order to receive the proper credit, you must first call customer service before returning any product and all must be in it's sealed, original packaging. Opened or used product is subject to a 25% re-stocking fee. You must also have a RMA number which is obtained by completing a return form. Product Damaged in Shipping If your product was damaged in shipping, Do not return the product until one of our customer service represenatives instructs you to return the product. Your damaged product claim will process much faster after speaking with us first. Exchange Policy It is our goal to provide you with a safe and easy shopping experience. With that goal in mind, we do not exchange product. Should you need top return your product, you will need to re-order the correct product. We have found this to be a easy and simple alternative to the confusion of exchanging product. Please mail your package in a prepaid, insured, traceable method to the address below.