Kanex GoPower Watch comes with 4000mAh capacity battery and delivers up to 10 charges to your Apple Watch. Designed for the Apple Watch with the same magnetic inductive charging technology as the original Apple Watch charging cable, inductive charging is activated instantly when charger magnet aligns with the Apple Watch. Charge Apple Watch and iPhone simultaneously. Enables pass-thru charging feature. Your devices get charged first and then the battery pack recharges itself. Built-in surge protection for your device.