it is designed to be printed with 10% infill, 3 perimeter and 3 layers top and bottom. Rectilinear or honeycomb pattern infill. This case has crush zones in the corners and if you print with the limited infill, it will serve as additional cushioning. The holes are for m6 bolts. Im going to use hex head although allen head will work too. This is a work in progress and has not yet been printed. I may be changing the file in the near future and adding the infill manually in the CAD file so that there will be varying percentages of infill in different parts of the case. I used a calipers, stainless ruler and my trusty iPad1 to measure and draw it.