I recently purchased a set of three coral life hanging pendant lights. One is a 175 watt metal halide but the other two are the same shape light fixture just smaller and the ballasts are about the same size but nowhere as heavy or noisy as the 175 watt ballast. They also have a light plastic cover you can take off to access 4 dip switches and on the back it tells you how to set the switches to set how quickly the light powers up. There is nothing else on the ballast except on one of the cords. A sticker that says model is rp477 serial number 47701000 and it also says type A lamp. I'm trying to see what size bulb the fixture uses and one of the ballast wont light the bulb. I'm not sure if its the wrong bulb or a bad ballast. If anyone can help point me in the right direction or give me any info I will greatly appreciate it. O and one of the ballasts says corallife on the plug and the other does not. But they look exactly the same otherwise.