Bookman just made a good thing even better! Their slim, high quality bicycle light set gets a rechargeable USB upgrade so you no longer have to worry about batteries. Just like the original Bookmans, the Bookman USB is easy to mount, simple to use, and fits any and all handle bars and saddle poles. Despite its small size (which makes them super easy to stash in your pocket), the light is incredibly bright (even brighter than previous models) and features three modes (slow flash, fast flash, and steady) to suit your preference. The large, single button operation makes it easy to turn on and off even with gloves on, and it comes equipped with a micro USB connection and a mini USB cord so you can charge them up right out of the bag. There is also an indicator on the back of the light will start to flash when the battery is low and even then the light is programmed to hold a constant brightness so you can always trust the lights to be bright when you need them. Weather resistant construction, so you can use it year round. A must for the riders out there.