Hello all,I am a GPS RTK engineer from Tersus GNSS. It is a start-up company from Switzerland who make least expensive, reliable, centimeter-level positioning accuracy GPS RTK boards for drones, etc. The RTK boards can be integrated to other host devices or served as an independent GNSS receiver at a very affordable price.If you are interested and want to know details of technical specifications, drop us a line to info@tersus-gnss.com or visit our website tersus-gnss.com.