i think they are not made anymore so you must get them on ebay or at a second hand store. i just got 1 for 4bucks on ebay! they are a bit skinny imo at 4inches, i also have a 6inch cool tube which will hold a 1kw hps bulb, the 4inch is too narrow for such a large bulb! the bake-a-round is great for a 400hps cooltube.