Advance cpap will accept returns on any unopened product within 30 days of the original ship date. Shipping costs are not refundable. Please note that any product that has been opened can not be returned. To avoid this, we make every effort to help you be sure of sizes and features of all items prior to purchase. We offer detailed product pages, a mask sizing guide. As always, please call us if you have any doubt or question about your order before it ships.