 When the marked stack of bills is not used, it is stored next to a magnetic plate near a bank cashier, in standby or safe mode, ready to be handed over to a bank robber by a bank employee.When it is removed from the magnetic plate, the pack is armed.Once it leaves the building and passes through the door frame, a radio transmitter located at the door triggers a timer (typically at least 10 seconds), after which the dye pack explosively releases an aerosol (usually of Disperse Red 9) and sometimes tear gas, intended to destroy the stolen money and mark the robber's body with a bright stain.