The Radius-V Handlepost is forged from aluminum for strength and features patented Fusion™ technology for an incredibly stiff coupling with the frame and fork. The Radius Telescope handlepost is adjustable so no matter how tall or short you are, you'll get the riding position that is most comfortable. This Handlepost will only fit all Dahon Ahead systems on 16" & 20” wheel bikes originally fitted with an aluminium height adjustable handlepost. It does not include the upper handlepost section or the handlebar itself. Used on very many models and suitable to replace all internal fold (folding to the lefthand side) Aluminium handlebar systems. Top section which it does not include measures 28.6mm (diameter) Please note: this handlepost (lower supplied only) is Black.