This is a holster I made for my GMC-600 geiger counter/radiation detector. It should work for several models sold by GQ Electronics, as well as a number of their EMF detectors which use the same plastic enclosure.
My GMC-600 has the ability to work as a dosimeter which is a tool you keep on your person to gauge any radiation exposure that your body receives during a given time-frame. The problem is that the device is large enough that it's practically impossible to fit inside any ordinary pocket in ones pants or shirt. This is a holster which allows one to wear the device via a belt clip. This can also be used to mount the device in convenient work locations which may lack table-top space (like say, a vehicle). There are port-holes in the holster to allow the USB charging port to be accessed while seated and a slot to allow the lanyard to extend without becoming hung up. The holster was designed so the device could be inserted either end first since my device has a gyro and will auto-rotate the display to be right-side-up. Not all devices made by GQ Electronics have this feature, your milage may vary.
I recommend printing in the standing position if possible. You will want "support everywhere" unless your printer just rocks at printing extreme overhangs. There are three STL's: belt clip oriented for left and right sides (with opening facing forwards in both positions), and no belt clip. The blender file is included too. The belt clip is an early rev of one I designed for my Alinco HT.