This product is a genuine Panasonic coil sensor designed for use in specific Panasonic ceiling cassette inverter air conditioning units. It is compatible with models S-21/43PU2H5-1 and S-18/22PU1H5A-1. The coil sensor is a critical component in the air conditioner, responsible for monitoring the temperature of the coil and providing feedback to the system for optimal performance and temperature regulation. Replacing a faulty coil sensor with this genuine part ensures proper functioning and extends the lifespan of the air conditioning unit.