how do flat rate boxes work? 387 viewsJune 17, 2022ShippingShipping on eBay Shipping on Mercari Shipping on Poshmark 0 RAD140 June 17, 2022 0 Comments how do flat rate boxes work?Share this:TweetShare on TumblrWhatsApp RAD Changed status to publish June 17, 2022 0 Answers ActiveVotedNewestOldest Register or Login