Built-In Type Di2 Battery SD300 Type BT-DN300

With the same size as its predecessor, the slim DN300 battery can be housed inside seat posts or frames ensuring a clean aesthetic. Now with 3 ports, the DN300 simplifies wiring to front and rear derailleurs, supplying stable power at all times. The third port is for riders who seek the redundancy of Shimano's 12-speed Di2 wired option.