I sent the pics to my brother-in-law. He asked "how do they work" here was my response...
A 30,000 mhz transducer manufactured by Applied Ultrasonics has been set into the bowling ball with thermal-epoxy. The black ball collects solar energy which powers the transducer which sends out ultrasonic frequencies through the outreaching arms. The ultrasonic waves travel through the water column, up to 30 miles, replicating the sound of a school of injured baitfish. Predator fish such as bass and walleye pick up these sound waves on their lateral lines and are attracted by the sounds of an easy meal. The high frequency sound waves also break up low end aquatic plants such as filamentous algae keeping the arms of the device and the entire lake free of algae.
