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 & impact. The new EPS™ V2 Power Unit is an improvement with regards to aerodynamics, versatility, durability & 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 & the battery charger plug. This design choice benefits both the reliability & the performance of the system, which is also upgradeable. FEATURES & BENEFITS EXTERNAL OR INTERNAL MOUNTING: the new cylindrical format allows the battery to be mounted in a variety of positions, all of which confer an aerodynamic dvantage. SPECIALLY DEVELOPED INTERNAL CASING DESIGNED TO ABSORB ROAD VIBRATIONS & IMPACT: for maximum protection of the battery & electronic components on even the worst road surfaces. CASING WITH ULTRASONICALLY WELDED SEAMS: makes the system 100% waterproof INPUT/OUTPUT GATES for charging the battery &, when necessary, diagnosing the system & updating the firmware & Eeprom. DTI™ DIGITAL TECH INTELLIGENCE: the digital brain of the EPS™ drivetrain. DTI monitors & checks the battery, transmits & receives signals to & from the interface & controls & monitors the functions of the rear & front derailleur. The unit also checks for system faults, warning the user when necessary via an RGB LED & a buzzer.