This slide gives more details on physical characteristics of the new MF-RM series. On the left, one can see how the MF-RM is constructed; the inner layer is the conductive PPTC material, the next layer is the conductive metal foil electrodes, the outer layer is the protective epoxy coating and finally the tin plated copper wires that allow the device to connect to the circuit. Shown on the right hand side is a diagram of how the part is marked.