Wahoo Extended Battery for Wahoo Bike Case or Bike Pack 2.3 AmpHours of added power(1.5x that of the iPhone battery), adds up to 5+ hours of ride time. Actual increase may be greater or less than 5 hours depending on iPhone model, app used, features employed and other factors. USB connectionfor re-charging; MicroUSB connection for use with Wahoo Bike Cases Fits Wahoo Bike Pack for iPhone and Wahoo Bike Case for iPhone Mount piggybacks on the back of the Wahoo Cases and mounts to standard Wahoo bike mount and aerobar mount Water and shock resistant (IPX-5 certified)