They are best known for their bright light emission that is far reaching. Their tungsten is encased in a quartz tube filled with xenon gas. They may require more power when turned on but use much less of it to maintain brightness. Moreover, they have a longer lifespan compared to the halogens. They may seem better but they also present some limitations such as being more expensive as far as manufacturing and replacement is concerned. They are not easy to manufacture from their complex design. Their bright light cause a blinding effect to oncoming traffic which is undesirable and can cause dangers on roads.

OIL SEALS

The metal case is the exterior (or frame) of the oil seal, the principal function of which is to give rigidity and strength to the seal. The material of the case must be selected depending on the environment where the seals are to be used. Often the metal case is covered by the same rubber material used in the sealing element, which also helps seal the exterior of the oil seal in the housing bore. Common case material types are: