I've got a Cateye LD630, which uses a single AA cell. The brightness is roughly similar to lights like the Planet Bike Superflash. Compared to the Superflash, the LD630 is easier to remove and install, easier to change the battery, and has a more reliable switch (I had a problem with the Superflash turning itself on and off).

One nice thing about Cateye is that they sell extra mounting brackets, so I can move the LD630 between my bikes.

TL-LD630-R | CATEYE


Steve in Peoria