ROBERTSON 1P20132 OEM-Pak of 20 Fluorescent eBallasts for 2 F40T12 Linear Lamps, Preheat- Rapid Start, 120Vac, 50-60Hz, Normal Ballast Factor, NPF, Model RSW234T12120 /A (Crosses to 3P20010 Model RSW240T12120 /B) Equivalent to Philips-Advance REL2S40SC, Osram QTP2X40T12120RSNSC, Universal B240R120HP Equivalent to Keystone KTEB-240-1-TP, General Electric GE 97499, GE240RS120-DIY,Fulham WHCG9127T12RS Also available as a Quik-Pak of 10 units individually packaged as ROBERTSON 2P20132 Also available as a single quantity as ROBERTSON 3P20132 Take advantage of Robertson's 60 years of electronic design and quality manufacturing experience.