The Tunze MasterStream 6508.5 Magnet holder is one jumbo mounting solution which costs more than most propeller pumps. The MasterStream pumps are big honkin water movers with enough thrust to push a small boat, so they need a strong and stable platform on which to anchor. Most users of the MasterStream pumps will opt to permanently fasten their masterstream to fixed plumbing inside the tank. However, for large glass tanks using the MasterStream pump the 6508.500 Magnet holder can stay put on glass and walls with a thickness of up to 1.125 inches thick, or just under 3 cm. With a list price of $263, when the Tunze MasterStream magnetic tank mount is not holding up massive MasterStream propeller pumps, it also moonlights as a good investment in rare earth metals like Neodymium.