![Save the Post Office on X: "#OTD #OTDPostal Nov. 20, 2004, The Priority Mail Flat Rate Box is introduced, as part of a 2-year experiment. The boxes themselves are free but may Save the Post Office on X: "#OTD #OTDPostal Nov. 20, 2004, The Priority Mail Flat Rate Box is introduced, as part of a 2-year experiment. The boxes themselves are free but may](https://pbs.twimg.com/media/FEoxDKoXEAcCUHu.jpg)
Save the Post Office on X: "#OTD #OTDPostal Nov. 20, 2004, The Priority Mail Flat Rate Box is introduced, as part of a 2-year experiment. The boxes themselves are free but may
![USPS Flat Rate Box Shipping Sizes and Price Breakdown - How to Enable Flat Rate Boxes on WooCommerce - ELEXtensions USPS Flat Rate Box Shipping Sizes and Price Breakdown - How to Enable Flat Rate Boxes on WooCommerce - ELEXtensions](https://cdn.elextensions.com/wp-content/uploads/2018/09/WooCommerce-USPS-Shipping-Domestic-Label.png)
USPS Flat Rate Box Shipping Sizes and Price Breakdown - How to Enable Flat Rate Boxes on WooCommerce - ELEXtensions
![USPS Flat Rate Box Shipping Sizes and Price Breakdown - How to Enable Flat Rate Boxes on WooCommerce - ELEXtensions USPS Flat Rate Box Shipping Sizes and Price Breakdown - How to Enable Flat Rate Boxes on WooCommerce - ELEXtensions](https://cdn.elextensions.com/wp-content/uploads/2018/07/usps-flat-rate.png)