Rios of Mercedes | Natural Brahma Bison Boot – Outpost 。The image shows the inside of a pair of Rios of Mercedes boots, displaying two size markings: \"637N\" on the left and \"900EE\" on the right. These markings indicate the model number and width of the boot, respectively. The \"N\" and \"EE\" denote different width sizes, with \"N\" being narrow and \"EE\" being extra wide. The brand name \"Rios of Mercedes\" and \"Made in Texas\" are also visible on the tag. Rios of Mercedes boots are known for their quality and comfort, and are handmade in the USA. The fit of Rios boots can vary, with some models fitting true to size while others may run slightly small. If you are unsure about your size, it\'s often recommended to go a size wider, especially with stingray leather, which doesn\'t stretch.