Mackwell cerian sr642m3 is an emergency inverter for use with compact fluorescent lamps it can be used with 13 18 26 32 or 42w pl t lamps or 38 55w 2d lamps these inverters achieve ballast lumen factor within 60 seconds of starting they have a 4 pole change over relay for complete lamp isolation on hf ballasts and have a 3 hour duration this inverter should be used with a 6 cell battery pack