A worn plastic badge bearing a faded numerical imprint that seems to shift slightly when viewed from different angles. The surface has been chemically treated to resist standard Bureau scanning equipment, leaving only faint phosphorescent traces visible under specific lighting conditions. Thermal-reactive elements embedded in the material change temperature based on proximity to surveillance systems, creating subtle but detectable warnings about being monitored.

The Lost Number creates a persistent blind spot in Bureau surveillance that other players can detect but not fully understand. When holders achieve high placement, automated investigation protocols trigger automatically - but the Bureau cannot locate their records to complete the review. This makes Lost Number holders simultaneously suspicious and untouchable, creating paranoia about what the Bureau knows but cannot access.