This board is a simple adapter for 10 port pins (labeled D0-D7, VCC, GND), to split a male 2×5-pin header into two 2x5-pin headers connected in parallel. This allows you to monitor signals with an oscilloscope while the port is in operation, or to connect two devices to the same port.
The bottom of the board has a female IDC10 connector that will plug into a 2×5-pin male header on your system. The top side has two 2×5-pin male headers with the same pinout as the original system's header.
The pinout is labeled on the PCB to be compatible with the various 2×5-pin I/O port headers found on development systems by mikroElektronika. This board was designed as a means to test ports on those systems. The labels are arbitrary, though, so if your system's 2×5-pin header has VCC on pin 1 instead of pin 9, for example, you just have to keep in mind that your VCC is on the EasyTEST pins labeled D0, and so on.