This is a replacement part for the AutoMixer v4 large pump. It can be placed in any of the three positions for the large pump, but you will need to ensure that the dipswitches on the JBT-BT driver are the same on both pumps.

Go here to learn more about changing pumps on the AutoMixer v4:

https://knowledgebase.agrispraydrones.com/pump-replacement-automixer-v4