Customized version of https://www.thingiverse.com/thing:59332

Created with Customizer! https://www.thingiverse.com/apps/customizer/run?thing_id=59332

Using the following options:

_part = box
_width = 36
_length = 36
_height = 12
_rounding = 28
_minimumWallThickness = 0.8
_sidewallThickness = 0.8
_horizontalThickness = 0.8
_magnetDiameter = 3.2
_magnetHeight = 3.2
_hingeGap = 0.2