Serfas Thunderbolt Taillight

Serfas' Thunderbolt Taillight delivers 35 lumens in an extremely versatile, USB-rechargeable package. Attach the water-resistant silicone body nearly anywhere on your bike, and use the high, low, or two flash modes to make sure cars or cyclists can see you when approaching from behind after dark. At just 50 grams, you won't even notice it's on your bike — but others will!