Why couldnt this be the 54w ones? Do you mind if i ask where you got them from? Been looking for the sd254-58 dimmable ballast fora few weeks with no result.
Yea ati sells all fixture parts directly now. Very good response time. I reached out to them about pricing parts for a project I'm doing. The 54w dimmable ballast for the sunpower is like 65 if I remember correctly. Not counting shipping. They responded to me within 24hrs! Keep in mind they are in cali when you send communication.