The Streamlight EPU-5200 portable auxiliary power source offers an instant charge for the company's line of USB flashlight products. Additionally the power unit charges smartphones, tablets and other electronic devices when a wall outlet is not available. It uses a micro-USB input and has an integrated LED for backup lighting. The EPU-5200 uses a 3.7V, 5200mAh Lithium Polymer battery with a safety control circuit to provide more than 500 charging cycles. The device weighs 5.4 oz and measures 4.45" long by 1.83" wide by 1.04" high. It is IPX7-rated waterproof to 1m for 30 minutes when its cover is installed and is impact-resistant to 2m. It comes with a removable pocket clip and a 5" cable, and it has a limited lifetime warranty.