BrainyTrade Mini Voice Amplifier Microphone Megaphone Loudspeaker (Can work with MP3, MP4, cell phone, and computer) Portable size, Easy to operate. Can make your sounds more louder,Can work with MP3, MP4, cell phone, and computer.It has a microphone input and a MP3 input. High performance-to-price ratio,High quality, good frequency response Low power consumption. Two lithium batteries, long battery life, up to 8 hours, charging low voltage protection function. Loudspeaker enclosure is ABS material, case with strap, can be worn at the waist. Suitable for teaching, tour guiding, sales promotion, and speech, etc.