The Petzl IKO Core Lamp is a lightweight yet high-powered headlamp for hiking, trail running, climbing, and skiing. The ergonomic design features 7 LEDs at a maximum of 500 Lumens and with a counterbalanced battery pack on the back. You can use AAA batteries or the included Petzl CORE battery pack that recharges directly via USB. It works equally well on the head, around the neck, or over a helmet, and you can even attach the stuff sack and use it as a lantern.