The HF18FF/A220-3Z1D is a type of relay manufactured by Hongfa. It is a through-hole, RoHS-compliant relay, featuring a single-pole double-throw (SPDT) switch, SPDT contact type and a maximum switching voltage of 24V DC. It can activate and deactivate high voltage electrical circuits. The relay requires no external power source and is activated by an electrical current, making it useful for controlling signals in various automotive, industrial, and home applications. Additionally, its coil has a resistance of 220 ohms and maximum power consumption of 0.4W. The relay also features five pins, including coil, normally-closed, common, normally-open, and ground.