Petzl Reactik $110
When the going gets dark, trail runners get out their trusty headlamp and keep going. We suggest this USB rechargeable, “intelligent” 220-lumen companion to guide you through a 100-miler. It has a reactive lighting design, meaning the Reactik automatically tweaks its brightness level based on the ambient light it senses in the area. Depending on the setting, the Reactik can also provide up to 12 hours of light from a single charge, good enough for a full overnight run.