If they are actually 100W they would be illegal - not that I suppose anyone ever checks....
Reading the add, I think they are 55W but the seller is claiming light ouput equivalent to a conventional 100W. No figures to back it up of course!
Am I the only one who gets annoyed by cars with too bright headlamps on the road? The dipping rear view mirror gets some use, but that doesn't help when they are coming towards you! With the spread of real Xenon HID headlamps, and these aftermarket ones the problem seems to be growing.
Oops, sound like a grumpy old man!