I asked him when I made the 29g fixture. only the XP-Es have premium and regular that he carries. I am going to be redoing the 120g fixture if I get a bigger tank and using XP-Es instead of XR-Es. The XP-Es are newer and more efficient and the XR-Es just have some optic choices that the XP-Es dont.

happy to help, its nice to use the stuff I learned to help others.