Stick one in and see, they only cost a couple of dollars :)

If you are the worrying type then be reassured that this light has been used for T8 and T12 bulbs by a great many people and unless they have radically changed the design just recently then you will be fine. No real drawbacks, your T8s will probably appear brighter than a T12 in the same fitting.

Help! I bought one of these light fixtures and the matching bulbs, but it will not work when plugged in. Does this thing have a pull cord I am not seeing? I opened the fiture up and didn't see anything. They also say to pull up on the sockets when you take it out of the box till they click in place. The openings in the housing are too large for that. I have plugged it in and just waited a while to see if it would light, but nothing. HELP!!!!!!

Did they not come with instructions? I can't do much to help without instructions or pictures.

If there's no switches or buttons to turn it on the only thing I can guess is that you don't have the bulbs installed right.