Unobstructed, free of interference, and when FCC-compliant. Maximum flight range specification is a proxy for radio link strength and resilience. Always follow local rules and regulations and fly your drone within your visual line of sight unless otherwise permitted. ** Vision positioning requires non-reflective, discernable surfaces, and adequate lighting. Available at altitudes from 0.5-30 m. The vertical and horizontal positioning accuracy is within ±0.1 m.