Features: Built in a 5V 2A USB output port; Built in a 5.5×2.1mm Female DC hole. 7.4V output Battery Size is approx. 75mmx71mmx40mm 100% Compatible with original manufacturer equipment including chargers Absolutely no memory effect; you can charge battery at anytime Low impedance battery design 12 months warranty. This battery is a high capacity 8800mAh Lithium rechargeable battery package, builit in a 5V 2A USB port, can charge your mobile phone, pads, mp3 directly, and also built in a 5.5mm DC 7.4V output hole, so make this battery can widely used for many more digital products.