Be careful with the coiled wire where it enters the rear light. The insulation can pull out from the grommet so don't let the light dangle from the wire. Just be gentle with it, that's all. Save your receipt from REI and you will have the right to lifetime return if this should ever happen.

Fitting the rear light to the helmet was a challenge at first but once I had it figured out I have not had to fiddle with the mount at all. The mount for the rear light stays on my helmet even when the light is not used and has been there for over a year except for cleaning.

The velcro strap goes through a vent at the back of my Giro Aeon as pictured.