The Flea 2.0 USB combo is a great way to invest in Blackburn's ultra light, rechargeable front and rear lights at a savings. The Flea front light uses four super-bright White Nichia LED's to achieve a 40 lumen output at 17 grams total weight. A USB rechargeable battery produces 3-5 hours of run time. The Blackburn Flea rear light has 4 ultra bright red LED for night riding safety. The Flea rear light comes with a Velcro strap and a belt clip making it easy to mount almost anywhere.