EPS V4 Interface that can be inserted in any bar end or in the port of compatible frames Clean, fully integrated appearance & hidden cable routing The heart and brain of the system: it handles the communication between derailleur and shifters, system diagnostic, zero setting and ride setting. Dual ANT+ and BlueTooth LE antennas allow communication with most GPS computers & smart phones Synchro Shift option to enable automatic front shifting when reaching specific ratios Easy access to charging port IP67 waterproof rating Cables not included. Requires specific cables for frame mounting and for handlebar mounting.