We have a cylindrical north finder ER-MNS-09 that can be used for drilling rig probes.
It can self-align to find the true north direction with high accuracy.
It can display the attitude information of the drill bit and provide attitude angle and azimuth information.
If you are interested in it,I am glad to tell you the details.
Please PM me or post YOUR EMAIL ID in the comment, will send u to your email.
You can send a message to this email directly: ericco188@ericcointernational.com