I am a life long commuter and have tried all types of mirrors. Helmet mirrors are much better than bar mounted types and this is the best one I've found. The clamp fits around most helmet shapes and holds on tight. Instead of adhesive, a rubber coated loop grips the foam edge of the helmet. The arm doesn't bend or shake, because it's made from a spoke. No ball and socket joints to wear out. Eventually, if you drop your helmet enough, the edges will chip because the mirror is made of glass. I have two (racing and commuting) as does my wife.