Since sunglasses are fairly light weight, they often come in under the 13oz maximum for 1st Class shipping. 1st Class is a 2-5 day service, so in times of low shipping volume (like not around a holiday), this method is just as fast as Priority, but half the price. However, there is no option on the USPS website for 1st class shipping. What do? If you have a paypal account, you can print USPS labels through paypal and pay with your paypal balance. It also has a 1st class option. https://www.paypal.com/us/cgi-bin/webscr?cmd=_ship-now Don't forget to donate to the OpinionatedOakley Foundation for USPS Shipping Option Awareness. Pins and little ribbon thingies available upon request.