Petzl - NAO 575 Lumens RECHARGEABLE: no need to carry around extra batteries. Headlamp runs on an 2600 mAh Lithium-Ion battery with an integrated USB port for convenient charging 5 HOUR CHARGE TIME: with USB cable COMPATIBLE: with Alkaline and Lithium batteries REACTIVE LIGHTING TECHNOLOGY: headlamp automatically adjusts brightness to the needs of the user, offering a maximum of 575 lumens COMFORTABLE: adjustable headlamp for optimal comfort