This is a housing for one type of the cheaply offered voltage references found on Ebay or Banggood. These refences are commonly used to test the precision of a multimeter or any other kind of DC voltage meter.
Space is accomodated for the optional 15V battery, but the two pillars might need some trimming to keep the battery well in place.
Material is not exactly critical. PLA is fine. I used a semi-flexible kind of PLA.
When fastening the board into the housing make sure the screw top right is not touching the positive terminal of the battery. Use a plastic washer to prevent shortcircuits. There is usually a layer of solder resist on the PCB which acts as an insulator, but that is easily damaged.
Filament type is not critical.