USPS (U.S. Post Office) is used to ship all orders using First Class Mail or Priority Mail services. Both services include tracking numbers.
First Class Mail packages have a weight limit of 14 oz. Some orders with more than one sling can weigh over 14 oz. depending on the sling model and the leather used.
Packages weighing over 14 oz. will upgrade the shipping caluculator rates to Priority Mail and the First Class Mail option will not be shown on the shipping rate calculator.