The new DN300 Built-In type 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). - Compatible with thinner next-generation electric wire SD300 and systems after R9250/R8150 series - Li-Ion type - Capacity: 500 mAH |3.7Wh (+- 2000km autonomy) - Rated voltage: 7.4V - Charges through RD-R9250 |RD-R8150 rear derailleur using EW-EC300 Di2 Charging Cable (sold separately) - Fixing small parts included - Weight: 52g