With all products available for purchase, Liberty Sleep Apnea recommends that whenever possible, the purchaser should visit Liberty Sleep Apnea in person to ensure the correct fitting, adjustments or settings are put in place by one of our trained professionals. Liberty Sleep Apnea is not responsible for incorrectly ordered product or incorrectly fitted items. Each device, mask and accessory can have different outcomes to different individuals; therefore, it is important to know that these products work effectively with you individually and your prescribed therapy. Attached sizing guides and charts are recommended average sizing and should not be relied upon as a guaranteed size. Due to the nature of these items and devices, most respiratory devices, masks and accessories are non-refundable. Some stock merchandise may have a 10-day return policy. Refunds may be issued provided that the item is unused, in new re-sellable condition with complete original packaging, as deemed by store associate or management. For hygienic reasons, Liberty Sleep Apnea, under any circumstances, does not exchange or return used or open packaged products. Liberty Sleep Apnea does not re-use/refurbish old or used items. All items for sale are new, direct from the manufacturer in original packaging. The purchaser is responsible to know the appropriate size and model that is appropriate for their therapy and their devices before purchasing.