Sunlite 21500-su 20ar70/sp/12v 20w ar70 aluminum reflector halogen bulb, bayonet base sunlite halogen ar70 aluminum reflector bulbs can last up to 1.8 years with normal household use of 3 hours a day and display a brighter, whiter light than incandescent bulbs. This 20 watt, double contact bayonet based, ar70 aluminum reflector bulb offers a light output of 1400 cbcp, and has an average rated life of 2,000 hours. Great for portable lamps, ceiling fixtures, track lighting, showcase displays and most common residential and commercial lighting needs. Halogen bulbs produce more lumens per watt (lpw) and have a longer lamp life than standard incandescent lamps. You can lower operation costs by more than 30% by using fewer halogen lamps to produce a greater amount of light.