Shimano Di2 Batteries. Must purchase battery, charger, and power cable to complete the system. -All Di2 components on the bicycle require the same firmware version. Using Di2 components with different firmware versions may cause malfunctions -Use Di2 system checker to update component firmware from http://e-tubeproject.shimano.com/ -Compatible with thinner, next generation electric SD300 wires and R9150 and R8150 series systems -Features three SD300 wire ports -Shared fixing method with BT-DN110 -Built-in type