KNOG PWR BATTERY BANKNothing is worse than going on a long ride and then realizing your phone is about to die because you forgot to charge it. When one of your devices is about to die, it's nice to have a battery bank so you can recharge on the go. The Knog PWR Battery Bank is a backup battery for any Knog PWR light and also doubles as a backup battery to charge your phone, watch, Garmin, or anything that is USB rechargeable. It comes in three different sizes that have three different battery outputs. It comes with a USB cable to recharge the battery. Don't let your electronics die on the ride, get a Knog PWR Battery Bank. Features Battery bank to recharge your phone, light, computer, etc. CNC machined and water resistant when the cap is on Battery indication shows how much charge is left | Knog | Pwr Battery Bank Small