1.Replacement OE:31501, 33488, 33727. Upgraded 31501 circuit board has replaced the ordinary atwood 31501 circuit board. Adopting more precise craftsmanship, with a waterproof coating on the surface, corrosion resistance, short circuit prevention, long life. 2.Compatible with Atwood Hydro Flame Furnaces:7912-II, 7916-II, 7920-II, 8012-II, FA 79D, HF 80D, DC82 25-32, DC82 35-41, FA 76D, FA 78 25-32, FA 72D, 8500-IV Series, 8500-III Series, 85-II Series, 85-I Series, 8900-I DC Series, 8900-II DC Series, 8900-III DC Series, AFSD12, AFSD16, AFSD20, AFMD20, AFMD25, AFMD30, AFMD35, DFMD20111, DFMD25111, DFMD30111, DFMD35111 DFSD12111, DFSD16111 and DFSD20111 3.Specification: 12VDC RV Fan Control Pin Connect Board and EC Adapter 4.31501 circuit board e ignition control board is powered by 12V DC and sends a signal to open the gas valve and a high output voltage to generate an ignition spark to ignite the burner. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.