ELTEM / PROPA-U100 / Directional Loudspeaker, Super Directional Speaker, Ultrasonic Speaker, Directional Sound System for Museums, Exhibits, Art Gallery and Digital Signage – Black : Amazon.ca: Electronics
Portable Ultrasonic Directional Speaker with Focused Audio -WS-M1 Work with Rechargeable Battery Wireless Connection
Super directional speaker kit - SWITCH-SCIENCE
Super Directional Ultrasound Loudspeaker with Amplifier Wall Mounted Long Distance Spotlight Directional Speaker - China Directional Speaker and Ultrasonic Loudspeaker price | Made-in-China.com