Each of the Launchkey Mini models has different functionalities. Below is an image of each to help determine which you might have, as well as the start of the serial number for each:

Launchkey Mini MK1

Serial number starts with 'LH':

This features an orange base.

Launchkey Mini MK2

Serial number starts with 'A39':

This features a green base.

Launchkey Mini MK3

Serial number starts with 'A4':

This features a black base, pitch and mod touch strips, and can be used with Components to customise it and update the firmware.

Launchkey MK4 Mini 

Serial number starts with either 'LA' (Mini 25) or 'LB' (Mini 37):

This features an OLED display, along with a black base, and pitch and mod touch strips. It can be used with Components to customise it and update the firmware.