This product is a wireless voice amplifier. It features 2200mAh batterry for long time use. It amplifys and relieve your throat stress. The amplifying sound is clear, crisp, no noise and no distortion and covers about 1000square meters, loud enough for daily use. This product is the best protector for your throat. Features -Color: Black. -Material: ABS. -Size: 9x8.4x2.8cm. - Battery Capacity: 2200mAh - The amplifying sound is clear, crisp, no noise and no distortion. - Compact size and light weight. You can use the back clip to fix it on your belt or pocket. You can also use waistbelt to tie it around your waist or it on your neck. - Built in 2200 mAh rechargeable lithium battery. The working up to 10 days after charging. - Supports (Micro ) playing MP3 audio playing: Repeat single tune, loop all music and songs. - The headworn microphone is adjustable. You can adjust the distance between your mouth and the mic. - Suitable for teacher, singer, , tour guide, etc. Package list: 1 x voice amplifier