Applicable model: Fit for all 40403-001, 40403-002, 20054502, ST9120A, B or C blower controllers. Also replaces part # R40403-001, R40403-002, R40403-003, 20054501, ST9120C 2010, 1138-83-1002A, 87H88, R20054502, R38493B001, 87H8801. Replaces other part # 1138-100, 1711, HCSI PLC=0, 164322, T9AV5D12-22, 16391, E 94V0, 1138-83-1003A. Please confirm your model before purchasing. Function: The controller receives the input from the thermostat (W, Y and G), pressure switch and high temperature limit switch input. The controller also provides user-selectable blower delay through dip switch settings. The 24-volt circuit of this controller is protected by a 5-amp replaceable automotive type fuse. Effectively controls the operation of the 2-speed blower motor and induction motor, and adjusts and protects according to the input signal. Material and Installation: This control circuit board is made of High-quality material, which has good moisture resistance, stable performance and long service life. The installation process is easier because no additional wiring kit is required. In addition, it works well with both the for original-wiring and the updated wiring, ensuring a solid and reliable connection. Operating line voltage:85 to 135 VAC, 50/60Hz Secondary control voltage:18.0 to 30.0 VAC, 50/60Hz Maximum blower load:15FLA, 30LRA, 120 VAC; 7.5FLA, 15LRA, 240 VAC Maximum inductor load:3FLA, 10LRA, 120 VAC; 1.5FLA, 5LRA, 240 VAC Humidifier terminals:8A, 115 VAC Electronic air purifier:8A, 115 VAC. Colour:As Shown Material:Metal Package Contents: 1 * Furnace Blower Control Circuit Board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.