this is wat i found not sure if its helping tho...
T6 Fluorescent Lamps - THE NEXT GENERATION of T5 lamps are direct replacements for standard T8 or T12 fixtures. No need to buy expensive T5 fixtures, or retrofit existing fixtures to use shorter T5 lamps. T6 have standard bipin (G13 base) connection, and are standard lengths (24, 36, and 48). These lamps have thicker glass, which makes them more durable, and they operate at slightly lower temperatures than standard T5 lamps. The lamps will operate with T8 electronic ballasts, and T5, 54 watt ballasts. The T6 Fluorescent Lamps provide 10% to 40% more light output than standard T8 fluorescent lamps.
These fluorescent lamps are excellent for new High Bay fluorescent fixtures using standard T8 lamps. Increase light output significantly by using or changing to T5 ballasts, without buying expensive T5 fixtures.