Campagnolo: The new design allows for INTERNAL mounting which not only offers the obvious aerodynamic benefits associated with hiding a component inside the frame but also keeps the unit protected from the elements and impact.The new EPS V2 Power Unit is an improvement with regards to aerodynamics, versatility, durability and protection but also plays a pivotal role in an aspect that is not to be overlooked; aesthetics.The new EPS V2 Power Unit gives the cyclist the possibility to use the most advanced groupset while maintaining sleekest look to his or her ride.The brain of the system. The EPS Power Unit is much more than just a battery. Its housing contains all the electronics of the EPS drivetrain, the system memory input/output gates and the battery charger plug.This design choice benefits both the reliability and the performance of the system, which is also upgradeable.