| Size | Generally, range from a few meters to over 20 meters in diameter. |
| Speed | Exhibits capabilities for both hovering and high-speed flight, often making sudden sprints. |
| Signatures | Radar detection varies, visual sightings more common. Some reports include a humming sound. |
| Colors | Metallic silver or gray is common, though some have been reported as emitting light or changing color. |
| Surface Details | Variations include smooth, featureless surfaces to those with visible domes or segmented panels. |
| Behaviors | Sudden vertical ascents, hovering, and silent operation. Some reports indicate the ability to become invisible or blend into the sky. |
| Unique Emissions | Instances of electromagnetic interference in nearby devices and vehicles. |
| Atmospheric Phenomena | Visual disturbances, such as shimmering air or sudden fog formation. |