Goodlite G-20372 Straight 40-watt 48-Inch T12 Fluorescent Tube Light Bulb, Daylight, Pack of 24 G13 Medium Bipin, 48" long, Good Efficiency 75% less energy than incandescent, CRI 78 2800 Lumens More than 80++ lumens/watt (efficacy) Bulb Meets Federal Minimum efficiency Standards Works with INSTANT/RAPID Strat Fixtures, Long Life: &gt;20,000 hour ,Bulbs sleeved safe wile shipping Energy efficient, high energy savings in an environmentally responsible lamp Environmental responsibility and low mercury meets TCLP, Brand Cross Reference F40T12/DL - F40T12/DL/ALTO - F40T12/DL/ECO