Serfas TSL-S500
  • 500 claimed lumens
  • 1h 45min reported battery life
  • Spot
  • 150 g
  • flashing mode
  • no pulse mode
  • 4 brightness levels
  • internal Lithium batteries
  • low battery indicator
  • removable battery
  • mini usb rechargeable
  • Included mounts: Strap
  • Optional mounts: Helmet

The TSL series includes Serfas' single-piece USB-rechargeable lights, designed for commuting, road biking, and off-road rides.

The Serfas TSL-500 has since been replaced by the TSL-550.

Review: High-intensity light but a too-narrow beam

Review by , Sept. 12, 2013, midnight


  • User-replaceable li-ion battery.
  • USB rechargeable.
  • Very bright (although the beam is too focused for my tastes - see below)
  • Versatile mount (takes some getting used to, but great once you’ve figured it out). The light is very, very difficult to clip into and out of the mount, but, the mount is extremely easy to remove from the bike. I've found it easiest to keep the light in the mount, and quickly snap the mount on and off when I need to remove the light.
  • Includes helmet mount.


  • Very focused beam doesn't cover the whole road, and gives an intense "white spot" area that can detract from night vision. The next-generation TSL-750 light debuts a new interchangeable lens which should solve this problem.