Mine says "Wonder" and "Type ATUVU". The switch would always go bonkers. The strap would dig into my leg, right above the calf. Some guys used them on their arm, but I thought it was more effective on the leg, moving up and down. I only used it when I "had" to ride at night, after a training ride at Skypark Circle, Como, or the like.
Wes Oishi
SoundCycles
Los Angeles CA
USA