Lately our bedroom closet 4ft 40w with 2 bulbs is taking a long time to turn on, sometimes a few seconds, sometimes a few minutes but over the last few weeks it has been getting worse and worse. I tried changing the bulbs but that didn't help. Then I decided it must be ballast. After I found out that my original Universal 446-L-SLH-TC-P was no longer made, I offered to replace it. I cut the original yellow, blue and red wires next to the original ballast to allow enough slack to connect them to the new ballast. The installation went quickly. I just matched the colors and used wire nuts to secure them. After installing everything, I flipped the switch and they turned on immediately. It is much better than our original. And also very quiet. I am very satisfied with this inexpensive replacement ballast.