benzonline
those bulbs are interchangeable.
the 9003 is the u.s. dot version of the h4. it doesn't put out as much light as the [same] h4.
if you want to by an h4 bulb, tell the parts people you need them for a motorcycle.
do you want the "blue light"effect or a good performance bulb?
sylvania siverstars are pretty nice [9003].
philips vision plus is a h4 that has [claims] 50% brighter than stock 55/60 watt bulbs.
i have these in my euro's and am very satisfied with them.
they came from
www.powerbulbs.com
peter