# What does t5, t8, t12 mean?



## emoore3 (Oct 18, 2003)

They refer to the diameter of the bulb. They are all flourecent bulbs. T12 is the largest followed by T8 and then T5.


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## Rex Grigg (Dec 10, 2002)

Each T in this case equals 1/8th of an inch. And it's referring to the diameter of the bulb.


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## Jerm (Sep 26, 2005)

With a good refelctor, smaller is better.


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