ROBERTSON 3M10079 S40BP /A Fluorescent mBallast for 1 F40T12 Linear Lamp, 120Vac, 60Hz, Normal Ballast Factor, NPF Save and order the 2M10079 Quik-Pak of 10 units individually packaged Save the most with the 5M10079 carton of 10 units, not individually packaged Commercial grade. Two Year Factory Warranty Go to RorbertsonDirect.com for complete technical data. Take advantage of Robertson's 60 years of electronic design and quality manufacturing experience.