It has a compact tube shape and a clear shell (as opposed to frosted) for maximum light output.

 Email us if you need other replacement parts or more than one.

This is a long life 24,000 hour bulb. Be careful. There are many other "400" watt bulbs that are only 16,000 hour bulbs!  

The way the lamp life is measured is different too. After 24,000 hours, 67% of this auction's lamps are surviving.  At about 28,500 hours, 50% of bulbs are still burning. A standard horticultural 400 watt HPS lamp has 50% of the bulbs burning at 16,000 hours. Trickey light bulb salesmen often say these 16,000 hour bulbs are 24,000 hour bulbs too.

They are just playing games. Bulbs last the more hours you burn them at a time. So they assume they are burning 24 hours per day to get an exaggerated rating. What a scam!