With 300 lumens of power housed in a super compact, watertight body, the Cosmo 300 is perfect for urban adventures and overnighters in the woods. The Cosmo's new, compact body, is more ergonomic with a lower profile for improved balance, and the updated user interface includes a second switch for easy lens selection. In addition, the updated optical efficiency not only provides brighter light, but also saves battery life. And thanks to its watertight construction, the Cosmo keeps lighting the way whether you're forced to bike home in the rain, or you're hiking back to camp in an unexpected downpour. Black Diamond - Cosmo 300 Headlamp