Review on W WINBRIDGE Voice Amplifier: Portable Microphone and Speaker for Effective Personal Amplification – Ideal for Teachers, Elderly, Coaches, Training, Presentations, and Tour Guides by Rene Putman

I use this behind the mask so others can hear me while I speak behind the mask. Without them, you couldn't hear a word from me because it was so muffled. Now you hear me loud and clear. Works very well and comes charged. I'm not entirely sure about the battery life, but the sound quality is excellent. If you turn it up loud enough, you can actually hear whispers decently. Be aware that bringing the speaker too close to your mouth will cause feedback squeal. If you have it in the chest area or below, it will work without any problems. Great product for the price!