Hands-Free Auto Mapping: With precise positioning and distance measurement, E18 effectively maps your yard and plans the mowing path, which can be easily viewed on your smartphone. (Note: Subscribe to 4G data via the app for stable connectivity if your yard isn't fully covered by Wi-Fi.) Precise Obstacle Avoidance: E18's 3D perception system accurately detects obstacles, ensuring it avoids collisions in complex garden environments. Reliable Lawn Maintenance: E15 can achieve beautiful and uniform parallel cutting. Smart coverage detection system ensures no area is left uncut. Quality Materials: Made of superior high-carbon steel for improved performance and smooth cutting. Check Before Purchase: 0.3 acres (13,000 sq ft) max mapping area. For grass under 3.5' and flat lawns (height difference under 1.2'). (Note: Not suitable for St. Augustine and dense Zoysia. Slope < 18°.)