XXX-GLO bulbs T8 or T12

The XXX-GLO bulbs (Power, Aqua, Flora...) all have the small diameter that
has been mentioned as a distinguishing factor between T-8 and T-12 bulbs but 
I can't find any indication on the bulb or packaging that states which 
type it is.  Does anyone know what type of bulbs the XXX-GLO are?

I'm trying to find out since I'm having trouble getting these bulbs to
start without human intervention (a flick from my finger) and a T-12
ballast. It could be my ballast if they're T8 bulbs or a grounding

Ian McPherson
ian.mcpherson at nt_com