This is a case for the LCR-T3 variant of the quite wonderful universal transistor and component tester developed by Markus Frejek, and later Karl-Heinz Kübbeler. A full description of the project is available here:

http://mikrocontroller.net/articles/AVR_Transistortester

This case fits the variant with graphical display sold on Ebay and elsewhere called LCR-T3. The case includes a compartment for the battery, and gives access to the surface mount component test area. The pinout for the 14 pin ZIF test socket is printed on the case, for reference. Note that there are several different variants of this tester in the market. This case is only designed to fit the LCR-T3.

There are two versions of the case: One with a lid for the battery, and one without it. The version without a separate lid is recommended.

You need four M3x15 countersunk screws for assembling the top and bottom sections. If you choose the version with the lid, you also need a short M3 countersunk screw to secure that.

Note that the PCB for this case is the T3. The T3 is somewhat similar to the T4 PCB, but it is not the same, and does not fit the same case. There are also other variants out there. Please examine the pictures of the PCB carefully to make sure you have the right PCB before you start your print. A case for the T4 is available here: http://www.thingiverse.com/thing:797733 Yet another case is here: http://www.thingiverse.com/thing:1580922 A case for a variant with alphanumeric display is here: http://www.thingiverse.com/thing:641003