Here are the Magnetek and Grainger part numbers for electronic ballasts. 2 24" Magnetek B232I120RH Grainger 3V953 4 24" Magnetek B432I120RH Grainger 3V957 2 48" Magnetek B240R120RH Grainger 3V959 4 48" Magnetek B440R120RH Grainger 4VC88 Paul