Halogen headlamps look like a conventional sealed-beam lamp. However,these guys are a lamp within a lamp. There is a small halogen bulbinside the sealed-beam lamp. Inside the halogen bulb are two filaments.The low-beam filament is shielded, just like a conventional sealed-beamheadlamp. The high-beam filament is unshielded, for more light inhigh-beam mode. The halogen bulb is considerably brighter than aconventional sealed-beam lamp.