Recently bought a cpe-2 but with out a tank. I already have a 1520 and I am think of buyng the extension to develop 5 rolls together. But from what I have read, I need the magnet to put ine base of the tank to connect to de cpe. Were I can find one on-line shop that sells that. From my research, I can only find the several tanks, the extension modules and other acessories!