The Cetus is a small drone with the somewhat unconventional addition of an optical stream sensor. Not only does this give drift-cost-free hover, but a delicate automated landing when the battery is failing – both large boons for beginners. Even so, the aircraft's 203 x 203mm pusher frame is 236.6g https://andy43s72.total-blog.com/getting-my-drones-statistics-to-work-53508964