This is a case for the USB tester combo board by Fried Circuits. That boards comes as a bare PCB and when you don't need all the test points, this case packages it up nicely.
If you don't have a printer that can print this properly (FDM might not work), you can order one at https://www.shapeways.com/shops/liyanage. The model is offered there with no markup on top of the Shapeways price.
Printed with Clear v2 resin