Voice Amplifier: The wireless lavalier microphone also supports magnetic suction, which can be easily adsorbed or clipped to the collar, eliminating the discomfort associated with traditional headset microphones, it greatly reduces the burden of teaching and provides flexibility for different speaking situations Original Clear Sound: This portable voice amplifier has 76MM anti-interference Inner-magnet horn effectively amplifies your voice and protects your throat, allowing up to 100 students to hear you clearly. Built-in noise reduction chip to achieve no noise feedback, no whistling, output clear and soft sound Dual Wireless Microphones:The personal voice amplifier contains two microphones, which can be replaced at for seamless battery life when used by a single person; when used by two people, the speaker receives two voices at the same time for multi-scene adaptation & Portable:this portable microphone and speaker is compact and easy to carry. Comes with an adjustable strap so you can wear it comfortably around your waist or sling it over your shoulder Widely Compatible: This Bluetooth voice amplifier also supports U disk, easily connect to your cell phone//PC via Bluetooth for a hassle-free audio experience. Great for teaching, training, coacher, tour guide, shopping mall, speech, outdoor singing, etc Colour:Black Material:ABS Package Contents: 4 x Microphone 2 x Receiver Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.