Two. The 15km transmission distance can only be achieved beneath the FCC regular when calculated in an out of doors natural environment without having interference. The SRRC conventional is adopted in mainland China, along with the furthest transmission length is 8 km. Mavic 3M with RTK module for centimeter-amount positioning. https://m3mhomes.com/commercial/m3m-route-65-sector-65-gurgaon/