ITEM NAME:Soldering Iron Station Control Board Controller Thermostat A1321 For 936 BX.The circuit board can only be equipped with a1321 type heating core. The heating wire resistance: 2.5-3.5 ÃŽ ©. Sensor resistance: 43-58ÃŽ ©. Application:only for 1321 Heating core. Heating wire: 4, 5 feet.