Shimano BT DN300 Built In DI2 Battery Mountain Bike Helmets Pass-through channels allow eyewear to

Pass-through channels allow eyewear to be easily stored on the front of the helmet

Cassette/Freewheel 18t

Keep away from heat

520mm width

8mm XS: 670mm (27

Shimano BT DN300 Built In DI2 Battery Mountain Bike Helmets Pass-through channels allow eyewear to"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