I tried the dewalt bulbs in the past. They aren't really very good. You can probably get 330+ lumens out of the 18V one, but you would probably need to use 7 or 8 in a series. The voltage of the 123 will drop to about 2.5V under a significant load. The biggest problem with these bulbs is that the filament is HUGE! This means that it is pretty impossible to focus and makes nasty rings everywhere. Save the money and get in on a Carley or Welch Allyn group buy.