Specification: Item Type: Voice Amplifier Material: ABS Weight: Approx. 405.0g/14.3oz Rated Power: 5W Resolution: 80dB Distortion: 1% (3.7V, 1KHz, 1W) Signal to Noise Ratio: 83dB Working Voltage: DC3.7V Charging Voltage: DC5.0V Battery: 18650 battery x1 (not included) Display: LED Display Speaker: 2.5 in x 1 Audio Format: MP3/WMA/WAV Working Temperature: -5°-40° Support 32GB Memory Card How to use: 1. Put the microphone in front of your mouth for maximum amplification. 2. A certain distance should be kept between the microphone and the speaker, and the speaker can be hung on the waist 3. Turn it on, and finally increase the volume gradually as needed. Package List: 1 x Voice Amplifier 1 x Charging Cable 1 x Waistband 1 x Wired Microphone 1 x Manual