To show you how screwed up they are at our post office they were told to use the wrong size gauge a year or so ago. I even showed the senior clerk a copy of their web page for determining if something is a large envelope or a parcel and his response was "I don't care what it says!". Accoring to him if it was over 1/4" thick it was a parcel. I now use the automatic machine and control how much I pay myself.