Countersurveillance technologies
+7 (495) 223-62-22

Thin semicircle ultrasonic jammer SEL-324V

SEL-324V is a thin, small size microphone (including cell phone microphones) and audio recorder jammer with semicircle-shaped jamming pattern for deployment in environments with complex geometry: under desks and tables, inside automobiles, and other.  

Ultrasonic transducers in the SEL-324V are installed in a thin (the height of the device is only 25 mm), single-line sector-shaped array, providing reliable jamming within a 180° sector-shaped area around the device, which makes it a perfect choice for manual installation in meeting rooms and automobiles.


  • An array of 24 high-quality piezo-ceramic transducers, installed in a semicircle shape, controlled by a microchip that automatically shifts the noise signal in time and frequency domains, achieving best possible jamming efficiency and rendering any actual speech signal on the microphone unintelligible.
  • Flexible power supply: device can draw power either from the 220V mains, from a car 12V onboard power supply socket, or from a built-in Li-Pol battery, with capacity enough for 3 hours of continuous operation.
  • Easy to use control: can be turned on/off via a button switch on the device, or wirelessly with a special RF remote control.
  • Indicator dashboard: device constantly gathers self-diagnostic and battery charge data and outputs it to an easy-to read LED indicator dashboard on the bottom panel of the device.
  • Optional magnetic mounting system (please, send an explicit request for this option during your order).

SEL-324V standard package contents:

  • SEL-324V jammer, black color finish;
  • Power supply adapter for 220V mains;
  • Power supply adapter for car 12 V lighter socket;
  • RF remote control with spare CR2032 battery;
  • Owner's manual;
  • Cardboard shipping box.
Generated noise frequency bandwidth 24 - 26 kHz
Number of ultrasonic transducers 24 pcs
Jamming direction sector (180°)
On/off switch button or RF remote control
Average effective jamming range 4 meters *
Operation time from battery not less than 3 hours
Time to fully charge battery not more than 3 hours
Case material plastic
Overall dimensions R150 х 300 х 25 mm
Weight not more than 500 g
Operating temperatures from 0 to +50 °C

* Effective jamming range may vary based on type of microphone of the audio device and its relative position to the jammer.