This is a basic plastic protector for the A20-OLinuXino-MICRO-4GB board. It consists of two plexiglass plates, eight M3 screws and 12 plastic washers.
Room for optional hard drive The four inner holes and the shorter screws allow you to install a 2.5" SATA HDD, as shown below:
Access to all connections, slots and buttons The laser-cut plates exactly match the size of your A20-OLinuXino-MICRO board (5600×3250 mils) and leave access to all the board's interfaces. Here is a picture of the enclosure fully assembled with the board installed:
Note that the tall capacitor C202, the Ethernet connector and the 2x USB Host connector remain exposed out the top. Note also that this doesn't entirely enclose the system, as the sides are fully open. It's more of a protector than an enclosure.