NiteRider's Lumina 500 will guide you safely home. This bright light puts out up to 500 lumens for up to 18 hours and weighs in at only 172 grams! Attachment is easy, too, on handlebars up to 31.8mm in diameter. There are four modes to choose from: high, medium, low, and energy-saving walk. Plus, you can charge it off a computer's USB port!