Monoprice 2500mAh Battery Backup for iPhone/iPod and Other Mobile Devices - Retail Packaging - Black The Monoprice 3-in-1 LED Light Hand Warmer and Battery Backup is the all-in-one essential accessory for the person on the go in the colder climes Use the LED Light to illuminate your car or front door lock when you get home late at night Use the battery backup/charger to recharge your cell phone or other devices when other power sources are unavailable