Lumens are the measure of light output. The higher the number of lumens, the brighter the light. For urban running, a lower number of lumens, like 150, will suffice. For hitting the trails at night, however, you'll want something more powerful. The Knog Bilby Run, for example, packs 400 lumens with a powerful beam reaching up to 100 metres.

Rest easy, our big-headed friend. Knog's headlamps are designed to fit most noggins and can be easily adjusted while you're on the move.