EPS V4 12x Interface All the communication from both the shifting levers and mode buttons are turned into specific actions thanks to the new interface. Not only does it take the electronic impulses and communicate them to the front and rear derailleur but thanks to its dual antennae internals, boasting both Bluetooth Low Energy and ANT+, it is capable of real time communication with a wide array of external devices ranging from smart phones to head units and more. While the external version bears a strong resemblance to its 11-speed predecessor a new internal interface has been developed, permitting assembly into either the handlebar or to specific frames with a dedicated interface area located on the down tube.