the holder i seen reminded me of the one you can get for the vortex diatom filter same idea as that one and where the tubes connect on top of the magum 350 it was a hard plastic type tubing that hung in the tank like the hot magnums uses. and one of these holders and a magnum 350 filter sold on ebay about 2 weeks ago i was going to bid but i didnt it sold for close to 70.00 + shipping, i wish i would have saved the pics they showed of it set up. that was the only one i have ever seen. now i am going to hunt and dig and try and find this holder i am sure they are laying around in peoples basement or junk rooms i want one lol i think the ebay seller said it was made by maineland for the mag 350 im sure they didnt just make one holder there have to be some more around.