Diode Resistor??

On the heating element , in the front there are two wires,in between is a little black component,then there a white
Diode Resistor, what is the Black component? and what are the numbers size for the Diode Resistor, so I may go buy it, and have it soldered in the unit. Should I buy this Black component also? if so what is the number and name of this
object? Thanks