It is used to amplify the speaker's voice, and usually comes with a headset microphone or a lapel microphone, and can be hung on the waist or shoulder. Its features often include: * 🔊 Amplifying sound for teachers, guides, or at events. * 🎤 Wired microphone. * 💾 Playing MP3 files from USB or memory card (depending on the version). * 🔋 Rechargeable battery