HAPEX Nano is a passive Particulate Matter data logger with game changing specifications. It was specially designed to monitor Household Air Pollution Exposure in households using dirty fuel for their energy needs.
This communication cable allows you to connect the HAPEX Nano to your computer. It is not a standard USB cable. There is a FTDI chip inside the cable that translates the HAPEX Nano communication protocol into a standard USB protocol.
It is sold separately because you might not need one cable for each device that you buy.