secretly suppresses the operation of the recorders by radiating special interference. Does not make any acoustic noises when working. Possible to jam >85% types of analog recorders and ~50% types of digital recorder (except integrated with mobile phones).
creates a noiseless powerful barrier to the microphones in modern phones iPhone, Samsung and others, as well as advanced voice recorders Edik mini etc. Does not disturb to listen companion but make not possible any audio recording.