As stated by the Audi Collection website, regarding the new Audi DUO “While quattro® refers to the revolutionary permanent four-wheel-drive system Audi developed over 30 years ago, the name duo refers to versatility of this amazing bicycle – to its ability to serve as both a work of art and a mode of transportation – and to its ability to blend beauty and craftsmanship with performance and technology. The four rings; available soon on two.” Amazingly the DUO is hand crafted in our beautiful city of Portland, Oregon by Renovo Hardwood Bicycles! Stay tuned for more updates and be sure to be on the lookout for them in the city! We are bound to see soon – Portland loves it bikes!!