bike wheel lights

The lights themselves are really bright and easily get you seen.
The battery compartment however is to small for any of my AA batteries to fit, the one battery that did fit was so tight I don't think I would get it out once it had depleted. I therefore had to use AAA batteries and pad then out with foam and tin foil. This allows the lights to work but they do cut out periodically when going over bumps.
Bought another set from a different manufacturer now and no problems.