It's got 4 light settings; a) slow strobe, b) slow double flash strobe, c) fast strobe, d) full on.
It's a clever design, fits really snuggly around the shaft of my scooter and looks neat! It's also incredibly bright!
I'm thinking I might move it to the centre of the handle bars, but that'll mean taking the shaft apart... maybe another day ;o) I think I'll get rid of the handle clip too (the bit above the light) as I never fold my handles down. Perhaps it'll be useful for a pimp later on though?