Here are the specs off of their site.
- 60% brighter than conventional sealed beam headlamps
- H4 60/55 watt bulbs are replaceable
- Die-cast aluminum housing with a complex multi surface reflector that produces a wider beam pattern
- Unbreakable clear polycarbonate lens
- Gortex® breather allows heat to escape while keeping moisture out of the lamp assembly
- Lamp assembly can handle off road bulbs up to 130 watts
- Easy drop fit installation with no additional wiring needed
See on their specs they spec them based on using a stock bulb.
Zack