ASUS RT-N66R vs RT-N66U
What is the difference between the R and the U suffix models? Does R stand for Refurbished?
The (R) just designates that the router is the retail version of the same router. Brick and mortar stores sell almost exclusively the (R) designated model, but if you purchase the same router from somewhere like Amazon you'll get the (U) model in most cases. And a quick google search for either router model (R) vs (U) will return results for both models.