Shimano SW-R9160 Dura-Ace Di2 TT Bar End Shifter Set Bike-Hydration-Hydration Systems-Rear Mount this helmet is proven to

this helmet is proven to boost cooling power by nearly 10-percent over Aerohead Ultimate MIPS while remaining aerodynamic

Flatlock seams

If you normally wear a half size:

the Uncollar++ helps ensure an effective seal from water entry at high speeds

2 x EPDM mounting O-rings (Small)

Shimano SW-R9160 Dura-Ace Di2 TT Bar End Shifter Set Bike-Hydration-Hydration Systems-Rear Mount this helmet is proven toA single programmable shifter button in each unit, designed to fit cleanly into aerobar extensions. Works perfectly with Shimano's Di2 Synchro Shifting: each "up" shift moves to the next gear ratio considering both front and rear derailleurs, each "down" shift does the reverse. Requires Shimano 9100 Di2 drivetrain. Can be installed as sole shifting point or used in conjunction with STI or brake lever Di2 controls. Shimano's Di2 technology provides