This collection of files will allow you to print out a reasonably acurate replica of the Sonix Victory 75 radio as used in Star Wars: A New Hope on the backpacks of the Sandtroopers. 

My recommendation is that you print the various parts at different quality settings:

• The radio back could be printed at just about any layer height since it has no detail and gets wrapped in leather/vinyl. 
• The faceplate works well at 0.2mm layer height. 
• For the various knobs and the speaker grill, go as high quality as you can.

The picture here is my finished prototype, smoothed with sanding and Bondo glazing putty. The knobs were printed at 0.1mm layer height. 

My final prop as will be used on my costume has buttons printed on my Form2 printer at 0.025mm.