Shimano BT DN300 Built In DI2 Battery

"The new DN300 battery features the same waterproof design that Di2 users have loved for generations. Now with 3 ports, it delivers stable power to Shimano&';s 12-speed road derailleurs and shifters (if a fully wired option is selected). 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. FEATURES Compatible with thinner next generation electric wire SD300 and systems after R9250/R8150 series 3 SD300 ports Shared fixing method with BT-DN110"