The merchandise under consideration is referred to as an electronic handheld whistle. The subject item operates at a frequency of 400±500Hz and the volume is 114-12 dB. The whistle is powered by 2 AAA batteries which are not included with the product. In use, the user holds the electronic whistle in their hand and presses a button to generate the noise which resembles the noise made by a typical mouth whistle. The electronic whistle will be marketed as a multi-use whistle to be used by coaches, referees and trainers.
[1] Please importantly note that only the relevant portion of the related is displayed above. You may refer to the said customs ruling for the entire ruling explanation.
[1]. https://rulings.cbp.gov/ruling/N321270