The Qbicle TANGENT fender applies the tangent line theory to aid in anti-splashing. It will lead water flowing from the fender to lateral directions with the Qbicle patented V-shaped inner guides inside of the flap. Sounds technical but works. The patented design can be installed with any frame, and fits in minutes with hex keys. Monostay Rear Fitment Road Bike 700c x 20-25 Weight: 110g. Single-Armed Stay: Alloy 8mm (O.D.) Hardware: Stainless Steel Fender length: 25.0 cm