Halogen, xenon, and krypton all refer to the gasses used to fill the bulb. Light bulbs are usually filled with a mixture of gasses, selected to help retard the evaporation of the filament and to minimize heat loss from the filament. Argon works OK for this, krypton works better, and xenon better still. The better gasses are more expensive, of course. Because flashlight bulbs are so small, it's relatively economical to use pricier gasses like krypton and xenon, so they're pretty common. Halogen, on the other hand, isn't a particular element or chemical. Halogen bulbs include small amounts of one of the halogen family of elements (usually iodine) in the fill gas. The halogen gas in the bulb can actually bond temporarily with evaporated filament metal, and redeposit the metal back on the filament. This extends the filament life and keeps the bulb's glass free of the filament deposits that make other bulbs turn gray as they age. There isn't anything mutually exclusive between krypton/xenon and halogen. Some bulbs are both xenon and halogen, or both krypton and halogen. In any case, the goal of both strategies is the same: to allow the filament to have a reasonably long life when burning at the highest possible temperature, burning more brightly and more efficiently.
UPC: 043168976695 , 20 Watt
||Single Halogen G4 bulb per Package 12V
||The Deck Store
||G4 | 12VDC |