I bought this to replace a melted INT 866 soldering iron. This is not a replacement, Aoyue does not sell a replacement for the INT 866 iron. The connector on this iron is the same, but all the internal parts are different. However, I was able to transfer the guts and wiring from the old "molten" iron (Station Int 866) to the body of this iron with minor modifications (cutting the board) and a new heater. As a result, I got a working system for my INT 866, but for this I dropped all the innards of this iron.