This is an upgraded IQ 2020 Heater Relay Board with jumpers & shortened screws for the front cover of the IQ2020. When part was upgraded, it went from three relays to two.Replaces the 74618 as of 9-10-2013What is included: NewUpgraded IQ 2020 Heater Relay Board w/ Jumpers & Shortened Screws for the front cover of the IQ2020Description: New(New as of 9-10-2013) This IQ2020 Heater Relay Circuit Board is the newest revision for the 2001-2009.5 IQ2020 Control Box. It's upgraded design provides a more efficient method of connecting the heater's power cord to this board therefore reducing fatigue on the two "beefed up"relays. The black wire from the heater's power cord now connects into the H1 position on the large gray terminal block. The heater's white wire (neutral) connects onto its own separate gray terminal block labeled H2. This will reduce stress on the relays and increase their lifespan due to better transfer of voltage. The ground wire connection remains the same. The incoming power wires and the black & white wire from the heater are inserted into the gray terminal blocks round holes by prying the gate open using a small screwdriver. This upgraded circuit board replaces the 1st, 2nd & 3rd generation boards in the IQ 2020 Control Box found in all 2001-2009.5 Hot Spring, 2001-2009 Tiger River and 2008-2009 Limelight spa models. Symptoms this part has failed: No power going to the heater even though the red HTR ON L.E.D. light is lit inside the IQ2020 control box. The heater board is charred on the front and/or the backside.Note: In older control boxes, you may encounter that a chip on this new heater relay board prevents the metal guard from seating properly and it may need to be trimmed. Visit backyardplus to watch video or download instructions.Note #2: This circuit board works in all countries