Review on Portable Voice Amplifier with Wired Headset Microphone Speaker - Louder Sound with Mask On, 18W 4400mAh, Bluetooth Support, Waterproof for Outdoor Activities, Teachers, Tour Guides - Whisper M800 by Amy Cummings

Used in a very noisy outdoor environment at a State Athletics Championships as a pole vault official. Although the loudspeaker of the match announcer in the stadium, which was installed on the scoreboard, worked constantly, my interlocutors could understand me perfectly. I used it for about 7 hours without charging. It is easy to work with, just read the instructions and test before use.