The Bodine B50 emergency ballast provides emergency operation for 90 minutes. Compatible with T8 and T12 lamps. Features test switch and charge indicator light. This ballast works in conjunction with the existing ballast on your fluorescent lamp to maintain illumination during outages. By working with a ballast, the B50 does not affect normal fixture operation and may be used with switched or unswitched fixtures up to 1400 lumens. Transform any fluorescent light into an emergency light with the Bodine B50.