Klein®, KTB2, Rechargeable Battery, Portable Jobsite, Lithium-Ion Chemical System, 5 V Nominal, 13400 mAh Nominal, 5 V Charge, 3 A Charge Current, 4 to 10 hr Charging, Plastic/Metal Case, Charge Every 3 Months Shelf Life, 25 hrs in 170 Lumens, 36 hrs in 100 Lumens, For Use With: Tablets/Cell Phones/Portable Batteries/Headphones/Headlamps/Other Smaller USB Devices, 3.5 in L x 1 in W x 5.7 in H Dimensions,