High volume, good sound quality and sound reduction, will be a nice choice for protecting your voice without straining your throat.

• Multi-function, can be used for power supply but can be rechargeable when it's out of power
• Built-in high-capacity lithium battery enables it to give you an ultra long playback
• When connected to a computer, it can be read via USB / TF card socket
• One-click recording, can record external audio, microphone
• Not only a voice amplifier, but also an FM radio
• Supports MP3 audio format

Specifications:

• Brand: Retekess
• Model: TR619W
• Charging Voltage: 5V
• USB Output: 5V 0.15A
• Output Power: 3W
• Working Voltage: DC 3.7V
• Frequency Response: 100Hz-20KHz
• SNR: ≥50dB
• Distortion Degree: ≤1.5%
• Speaker Power: 2Ω  5W
• UHF: 639-897MHz
• UHF Distance: 50m
• FM: 87.5-108MHz
• Battery Capacity: 1500mAh
• Working Time: 3-4h
• Charging Time: 4-6h
• Mic: 3.5mm
• Item Size: 129 * 87 * 46mm