I have always ordered my reptisun 10.0 bulbs from the same place (http://www.reptiledirect.com) and they have always sent me T12 bulbs (which is what I use). However, I received two bulbs today that were T8. First of all, on the website there is no option to choose which type of bulb you want, and second is this normal for them to be sending out T8 bulbs now?
I am a little dissatisfied right now and just venting, sorry...
actually the T8 bulbs will work in the regular T12 fixtures. I emailed the company I purchased the bulbs from and they said that they would work in the fixtures, so I tried it and they work like a charm.