Pettersson L400 ultrasound speaker

The L400 is an ultrasound loudspeaker with built-in amplifier that can be connected to any recording device capable of playing analog ultrasonic signals, such as the D1000X ultrasound detector or a computer with a high-speed sound card. It can be used for various playback experiments, as an acoustic lure and for teaching the use of bat detectors by listening to the sound from the loudspeaker.
A well-written guide on how to set up a bat lure can be found at Dean Waters’ blog.
 
Weight
1600 g
Dimensions
240 × 165 × 70 mm
Frequency range
10 kHz – 110 kHz
Power
8 x AA cells (built-in) or 12 – 28V external power supply
Max output level
>100 dB @ 1 m and 60 kHz (at 28 V supply voltage)
Features
Volume control
Level indicator
Rugged aluminium housing