Cement resistor: it is made by winding the resistor wire on alkali-free heat-resistant porcelain, protecting and fixing it with heat-resistant, moisture-resistant and corrosion-resistant materials outside, putting the wound resistor into a square porcelain frame, and filling and sealing it with special incombustible heat-resistant cement. The outer side of cement resistor is mainly made of ceramic material, which has the characteristics of large overall size, shock resistance, moisture resistance, heat resistance, good heat dissipation and low price, and is widely used in power adapters, audio equipment, audio frequency dividers, instruments, meters, televisions, automobiles and other equipment.