Voice Amplifier: Amplifies your voice and saves your throat when you have a difficult time speaking loudly enough. Delivering 5w clear and soft sound to cover about 20000 sq.ft (1000 ). loud enough to cover a big room Bluetooth: Not only an amplifiers but also a portable Bluetooth speaker, you can stream your favorite music from any type of Bluetooth-enabled mobile device, up to 33 feet away Light Weight: This portable Bluetooth Amplifiers is a portable public address system. You can take it to multiple locations such as classrooms, bingo calling and outdoors. A big help in speaking to 100+ members in your group Rechargeable: Built-in a 2200mAh big lithium battery allows the microphone speaker to only take 3-5 hours to fully charge, but plays up to 12-15 hours of amplify time and up to 8 hours of music playtime Music Playing: Personal voice amplifier TF (Micro SD) card playing & USB flash drive playing. You can repeat single tune, loop all music and switch songs,Easy to use as a wired speaker The compact size (7.6in x 5.7in x 1.9in) and light weight (0.45lbs) allows it to function anywhere, such as teachers, outdoors, etc. Compact in size, but with a built-in loud speaker capable of producing powerful results.