We partner with both UPS Surepost and UPS to ship our products. If your address is a PO Box, APO/AFO, it will ship via UPS Surepost. All other addresses within the continental United States will ship via a combination of UPS Surepost and UPS. UPS Surepost packages are shipped via UPS to your local post office and then delivered via USPS for the remaining leg of the delivery. This ensures that we can keep our delivery costs low and pass the savings on to you. Since the final delivery is handled by your local postal service, your order can be delivered 6 days a week, including Saturdays. For more details, read about our shipping policies here.