Shimano 105 FD-5800-B is a clamp-on front derailleur for 2×11-speed road bikes using a double chainring setup. It is suited to riders replacing a worn road front derailleur or building a Shimano 105 5800 drivetrain on a frame that uses a clamp-on mount and bottom-pull cable routing. The black aluminum-alloy construction keeps the unit lightweight and durable for regular road use. Shimano lists the weight at 89 g, so it is a practical choice for riders who want a traditional mechanical front derailleur with straightforward setup and reliable shifting on compatible 11-speed road drivetrains.