The KSD.301-100/103PAB with Thermostat Switches Through Hole RoHS manufactured by Xucheng is an electrical component that is used to sense temperature and control a circuit accordingly. It features three pins: a normally closed NC pin, a normally open NO pin, and a common pin. When the temperature rises above a certain preset level (the switching temperature), it creates a closed circuit, triggering whatever device is connected to the NC pin. When the temperature drops below the preset level, it opens the circuit, triggering whatever device is connected to the NO pin. This switch is suitable for both low current and high current applications and meets the international RoHS standard.