I have a PFO VHO retro that recently burned out one of the ballast. I opened it up and what is in side, WH 5. I also saw a guy on here running PC lights with a WH5. So the WH5 is good for PC, VHO and T5 HO? I thought read somewhere a TRUE T5 HO ballast was for the T5 only. Shows what I know. Thanks I can just buy caps, reflectors and bulbs and run three of the one WH5 I have left.