Common north seeker is generally rectangular or cuboid, especially the previous FOG north seeker and MEMS north seeker are cuboid form, but ER-MNS-09 is cylindrical form, as shown in the figure, its length is 120mm, diameter is 30mm. The cylinder is specially designed to adapt to a specific field, because the north seeker is mostly used in oil logging, mining, directional drilling and other fields, these fields usually need to meet the diameter of the probe, so that the equipment can be placed in the probe, so Ericco specially designed such a cylindrical north seeker.
At the same time, not only in oil logging, mining, directional drilling fields, the north seeker can also play a role in surveying and mapping systems, railway systems.
For more information about north seeker: https://www.ericcointernational.com/north-finders/mems-triaxial-north-seeker-for-mining.html