Support Dual Microphone Hands-free System AVerMic AW315 provides reliable operation with its dual-antenna to two wireless microphones. With 2.4 GHz wireless technology, noise and speaker buzz reduction, this hands-free design not only gives teacher total freedom to interact with students, it also delivers natural voice in great clarity and stability. Support Line and Mic out Mode AVerMic AW315 mode selector switch provides a simple selection in both Line out and Mic out modes. The Line out mode is suitable for common speaker systems with 3.5 mm Line In jacks, such as PC speakers or projectors with 15W or higher power speakers. The MIC out mode is suitable for classrooms with built-in audio systems and 6.3 mm microphone jacks. Wall-mountable You can secure or hang the AVerMic AW315/AW315C against a wall or cabinet with its mounting-hole design. Built-in Ground Noise Isolator AVerMic AW315 is built-in a ground loop noise isolator which can help to reduce the ground loop interference caused by a difference in ground potential and prevent EMI. USB Firmware Upgrade Function With this feature, it is more efficient for the users to upgrade the AVerMic AW315 firmware by themselves through the USB connection to a PC.