it's a m58. m58 is m58 is m58 (regardless of what brand sticker may be on it). which means it's made for probe-start 250w SE bulbs, like the XM15. for simplicity sake though, the same ballast from PGS in one of their nice boxes with the right quick disconnect is only 60 bucks new with purchase of the reflector. i'd probably stick this one in the closet as backup or sell it and buy the PGS ballast just to keep things clean and pretty. though i guess you could get their pigtail and dremel a hole in your box for it to snap into to be the same thing...