This is a case to hold one Next Thing Co. C.H.I.P. computer along with a LiPo battery holder. It's designed to be stackable and use one M3 machine screw (the kind used for PC optical drives) for the chip itself.

The tolerances are very tight. In practice, the CHIP and battery holder can be friction-fit. If your extrusion settings are off it may be that you will not be able to fit the components inside.