NiteRider's Lumina Micro 220 comes in a tiny package but puts out a huge amount of light. It delivers up to 220 lumens, lasts up to 14 hours, and weighs in at only 126 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!