Wow, It's like pulling teeth trying to get a bulb for my bike around here. It's 12v21/5w dual filament bulb, simple enough right!!!!!!!!!!! Wrong, bulb that came out is a 12499 and nobody knows what that is ( auto parts stores ) That must be a European model bulb said one guy. I hate to have to buy a couple bulbs on line. As it is I got no rear light, just a brake light.