Cheap Burners from Wal-Mart. 55W. I've got them aimed at the ditches to highlight critters on the move. I put a 100W bulb in one for grins, didn't put out any more light, but ran the battery down real quick. Update 6-19-05, I'm on my 3rd set of these. The lenses keep falling off. They are just glued on and I run them all the time. I'm afraid to buy an expensive set, I just know I'll drop the bike the day after.