Current USA Replacement SlimPaq 22 inch, 6700K, 24 Watt, T5 HO Fluorescent Lamp. 22 inches from end of pin to end of pin (for 24 inch fixtures/retrofits).

The Current USA T5 bulbs will work in any T5 fixture, as long as you are using bulbs of the same wattage as those currently in your fixture. T5 bulbs come in two categories, HO bulbs for Nova Extremes and NO for Nova Retrofits (NOs are either 9W, 14W, 21W or 28W--HOs are 24W, 39W or 54W). T5s are 5/8" or .625" diameter.