I have two dome lights in mine. A 45 and a 20. the 20 is just to brighten up the cage more on the one side and the 45 is for basking. I am just guessing that's what it might be!
yeah the 2 lights are different basking spots...the one on the right is more for light buts its at 85 for basking and the other is at 95..... he uses both...got a drainage set up from lll reptile too my cage is a 2x2x4 just got it...