ROBERTSON 2P20132 Quik-Pak of 10 Fluorescent eBallasts for 2 F40T12 Linear Lamps, Preheat Rapid Start, 120Vac, 50-60Hz, Normal Ballast Factor, NPF, Model RSW234T12120 /A (Crosses to 2P20010 Model RSW240T12120 /B)