Workhorse Ballast Commercial Grade. Replacement T8 commercial grade ballast for magnetic ballast, parallel lamp operation. Frequency - 50/60 Hz, ATHD: Meets ANSI CB2.11 -1993, Protection/Output: Open Lamp, Shorted Lamp, Protection/Overcurrent: Fuse, Protection/Voltage Transients: MOV (PER ANSI CB2.11 -1993, EMI/RFI: FCC PART 18-A.