This unit comes pre installed on a shimano dura ace 9000 left hand crank click here for the 4iiii manual improved battery life extend your battery life up 100 hours with the latest firmware upgrade weve also made improvements that make allowance for general sensor vibration so you no longer have to remove your battery when transporting your bike battery indicator now you will be able to see how much battery life you have left when youre out on a ride this battery alert will be transmitt