A device carried on the wrist that is used to temporarily disrupt machines. It is a small device upon a leather band.
- "On it she had strapped a wide leather band with what looked like a small brass jewelry case affixed to it. She flipped open the lid and held up the gadget for Sophronia to see. At first Sophronia thought it might be a music box, but when she looked closer, she saw there were all sorts of dials and wheels and small knobs." (Etiquette & Espionage, Lesson Eleven)