Genuine Daikin 011905J Thermistor Retainer is the clip that holds a thermistor firmly in place against the part it measures, keeping it in proper contact for an accurate reading. When it is broken or missing, the sensor can sit loose, read inaccurately, and the unit can run unpredictably. A genuine retainer holds the sensor exactly where your Daikin expects — where a non-genuine part can let it slip out of contact.