Metron 5D integrated handlebar, the stiffest and most aero integrated handlebar and stem system.  FSA Metron 5D 
Mixing aerodynamics and ergonomics, the unique shape includes our Aero-Ergo central section. With a slight rise from the stem clamp and a 10 degree forward bend, the 5D accommodates the natural position of your arms for more comfort and easier breathing, while the wing-like shape of the bar top aids aerodynamics. Reinforced carbon fiber construction gives a great strength-to-weight ratio. The 5D features internal cable routing, with guides that accommodate wiring for electronic shifting.