I have two Finnex 24/7 48". The transformers are KL-48A (15V 48W). They are both warm. It is ~3pm, so they have both been running at mid-day intensity for ~3hrs. I strapped an aquarium thermometer to the transform for 20 minutes, and it reads 105.8 degrees (+- 1 degree).
I doubt Finnex actually makes the transformers. They just put a label on it.