Can we make a quad-copter with a ducted fan and make it perform basic functions? What is good for a quad-copter, ducted or just normal propellers? Why? - Quora
Voyage Aeronautics VA-2140 Ducted Fan Aerial Drone-Hand Gesture- Blue Color, Size 3.75 inches - Walmart.com
SkyLite 3" Built & Tuned Ducted Drone - 4S in 2023 | Bardwell, Drone, Duct
World's First Bi-Rotor Ducted Drone Looks Like a Flying Donut Made for GPS-Denied Areas - autoevolution