I know. I thought I was the only one also as members I asked had no idea and there isn't really any detailed information about them. They do work really well. Are you putting LEDs on your 75 gall?
This is an old thread, but wondering if these fixtures were still serving you well. I bought a used 55 gallon setup that included the Aqueon modular LED with one daylight strip. Bulb suggestions to add for a low light planted tank?