The boxes are provided by USPS for free, and if your shipment is going to Zones 1-4, you'll find that this option is usually less expensive than Flat Rate Boxes. Priority Mail Medium Flat Rate Box ...

3.9 percent for USPS Ground Advantage and a larger 9.2 percent for Parcel Select. The price of a Priority Mail flat rate ...

Small gifts, such as socks, T-shirts and jewelry, may be best sent using the USPS Priority Mail Small Flat Rate Box for $11.00. This box is approximately 8 inches long by 5 inches wide by 1 inch ...