Ice Cap MH ballasts are great, but there are a few things to be aware of when purchasing them. There are old and new style Ice Cap MH ballasts, and if you want a ballast to fire any bulb, you'll need to purchase a new style ballast (identified by wires sticking out of the ballast).
The old style ballasts (identified by a Molex connector that needs to be attached to a wire harness) are great, in fact that's what I use and am very happy with, but there's a decent chance that they might need to be tuned to run specific bulbs. For example, I have two 175W old style ballasts. They're both tuned to run Ushio 10,000K bulbs, but I'm running a Ushio on one, and an AB 10,000K on the other. The AB runs on the ballast, but occasionally flickers. I contacted Ice Cap about that, and they told me I could either run a Ushio without problems, or send the ballast in to be tuned to the AB. When the AB goes bad, I plan on replacing it with a Ushio.
Most retailers that sell Ice Cap MH ballasts sell the new style ballast, and will even inform you that you are purchasing a new style ballast. If you are purchasing used ballasts, it's always a good idea to ask the seller what type of ballast they are selling.
