almost all current cygolites have a symmetric beam that isn't round. It's the same upside-down as it is right side up. They use a Fresnel lens. I forgot that one time on an undulating road where it would have been nice to have a little light higher up. Turned on the cygolite and got nothing extra because it does have a pretty good vertical cutoff. One of the few battery lights that does have a decent vertical cutoff. Now I have it aimed up a little and use it for descents sometimes.