This is a single ZEN stainless steel bracket and fan cooling add on that will expand an existing ZEN cooling kit to cover an additional flipper. It includes everything you need to expand an existing ZEN install to another flipper.
If you have a 2 Flipper kit installed select "2 Flipper to 3 Flipper Cooling Upgrade" if you have a 3 flipper kit, select "3 Flipper to 4 Flipper Cooling Upgrade." It's important to select the correct one because the 2 to 3 kit has additional required wiring.
If you have a 2 flipper kit and don't select the correct upgrade, you won't be able to connect it to power because it will be missing pieces.