They are designed to detect “metallic and nonmetallic threat items,” according to the TSA. Those are things like explosives or knives made out of materials other than metal, like ceramics, says Malvini Redden.

In 2026, modern TSA Advanced Imaging Technology (AIT) scanners use millimeter-wave technology to detect metallic and non-metallic objects, such as weapons or explosives, concealed under clothing. To protect passenger privacy, the scanner does not see or produce an actual image of your naked body. Instead, the software creates a "generic" human avatar or "mannequin" figure that looks the same for every passenger. If the system detects a suspicious item—such as a forgotten wallet, a dense buckle, or a hidden object—it will highlight the specific area with a yellow or red box on this generic avatar. This allows the TSA officer to perform a targeted pat-down of only that specific area rather than a full-body search. The technology does not store images and cannot "see" internal body parts or medical implants in detail, as it only penetrates a few millimeters past the skin's surface. Passengers can always opt for a manual physical search if they prefer to bypass the machine entirely.