I originally bought two of these lights for daytime riding with a strobe light. The selling features were the rechargeable battery with USB charging and four light modes; three different-powered steady modes and a strobe. I attached the mount to the two bikes, my wife's and mine. The mount is interesting: it allows you to swivel the light to point it sideways as you enter a corner, either for illumination or to catch the attention of a driver approaching from the side.
Be forewarned, though, the mount is a little small, barely fitting on 25-mm handlebars. No way could it mount on a stem.
Almost immediately we started noticing problems: one of the two lights kept discharging at about two to three times the rate of the other. Although the ON-OFF switch is supposed to display a red LED when the battery is below 15%, neither one of them ever showed anything but green, even just before dying.
We were discussing taking the light back to the vendor when one day the mount just snapped and the light fell off. We returned it for a replacement; the identical light. Two months later, the replacement stopped working entirely: the charge indicator glows green, but the light never comes on.
The other original light continues to work after about fourteen months, although it spontaneously turns itself off from time to time. When I returned the replacement, however, I asked for a refund. I bought a NiteRider Lumina to replace it.
I do not recommend this product: when it works, it's OK. The problem is that two out of three of the ones I bought didn't work.