Helmet-mounted rear lights sit higher than seatpost lights, which means drivers see them sooner over traffic. The Roc Loc 5 LED snaps directly into the fit system on compatible Giro helmets, integrating the light into equipment you're already wearing rather than adding another piece to mount and manage. The design positions the LED at the back of your head where it's visible from behind and to the sides without requiring straps, clips, or adhesive mounts that can shift during rides or leave residue on your helmet shell.

The light offers two modes: solid at 20 lumens with roughly 2 hours of runtime, or flashing at 30 lumens with up to 10 hours between charges. Flash mode is the practical choice for daytime visibility and longer rides, while solid works for shorter evening commutes where you want steady illumination. A micro-USB port handles charging in about 2 hours, and the LED indicator shows battery status in green, orange, or red so you know when to top it off before a ride. The unit carries an IP-65 rating for water and grit resistance, which means rain and road spray won't kill it. Output is certified to FL-1 testing standards, so the lumen claims hold up to independent measurement.

Compatibility matters here. The light is designed for Giro helmets equipped with the Roc Loc 5 fit system, specifically versions manufactured from late 2021 onward. It works with helmets like the Aries Spherical, Aether, Eclipse, and Synthe that use this retention system. The slim profile doesn't interfere with the fit dial, so you can still adjust tension and tilt with the light attached. At 20 grams, you won't notice the weight on your head. If you're already riding a compatible Giro helmet and want rear visibility without velcro-mounted lights that shift around or separate seatpost units to manage, this is the cleanest integration available.