Hi, I use a Petzl Duo. It is waterproof and has two bulbs, one halogen for longer distance beams and one standard for shorter beams. The focus on the halogen is adjustable. It works on four AA cells.They also have a new model, the Duo Belt, here there is a longer cable between the batterypack and the headlamp. It allows you to keep the batterypack in your jacket, backpack, or connected to the headstrap.I am really pleased with the performance and quality of the Duo.