A shoe last and a device for detachably mounting the last on a vertical surface that firmly supports the last permitting a user to conveniently polish a shoe mounted on the last. The first side bar, the second side bar, the third side bar and the fourth side bar are connected end to end. A third doped region is disposed between the second doped region and the undoped region. The channels facilitate cooling by directing fluid about the windings of the coil as fluid is introduced into the electromagnet.