I discovered through much trial and error the easiest and fastest way to calibrate the compass on one of these bad boys. I will try to make a video on that in the near future since I was not able to find a good description of the method anywhere. Long story short you picture north as 12 O clock and rotate it as if a rod passed through it east to west with the nose at 12, 10:30, 9, 7:30, 6, 4:30, 3, 1:30, and back to 12. Start it level with the nose pointed at those times with north always being at 12. West is 9, East 3, you get the idea. Keep the axis you rotate it along going from hand to hand if they were extended in front of you and face north the entire time. That green bar on the app moves at each time location after a rotation. If this method takes you longer than a minute it means I didn't explain that well enough.