Serfas Thunderbolt 2.0 Tail Light
A USB rechargeable rear light. brightness up to 50 lumens with a flash mode for daytime use. this light has a runtime of up to 19.5hrs.
other fetures include:
-2hr charge time
- safemode- light drops to the lowestblinking or solid mode for an extra 45 minutes after stated runtime.
- weight; 40g