Yep, Got it. They didnt have 18" Reptisun 5.0 bulbs so it didnt really matter...I went to 5 petstores and I coudlnt get a combo together! UGH!. I just made an order on dr.smithfoster so it should be here on monday
its all a matter of semantics, and the type of fixture you buy (and who you buy it from/its intended purpose), the fixture is always going to be longer than the bulb but, a 24" reptisun bulb is actually 23-1/8" for the bulb itself and the pins are about 5/16" (each end) giving the bulb an overall length of 23-3/4" to 23-7/8" (depending on manufacturing variences) my fixture/reflector is called a 24" fixture, but its actually a 24-1/8" overall length (and fits most 24" cages perfectly) and fits what they call a 24" reptisun, but the fixture / hood is always going to be at least a 1/4" longer than the bulb . some 24" hoods are actually exactly 24" and the fixture inside of them is for an 18" bulb. just be sure to verify which bulb the fixture inside the hood is intended for/edit/ if the bulb is in a green box, it is not a reptisun 5.0 unless it is a reptisun iguana bulb. ps reptiglo not the same as a reptisun, (but the measurement issues would still be the same), to see which fixture i am talking about view this thread https://www.chameleonforums.com/where-can-i-buy-30768/