HamiltonBuhl 12-Person BluetoothÂ® Wireless Listening CenterGo wireless in your classroom with plug and play simplicity.Connect to the wireless transmitter via BluetoothÂ® with your tablet, mobile device or any unit with BluetoothÂ® capabilities. Audio is then transmitted to a nearly unlimited number of wireless headphones via a wireless FM signal.Perfect for all multimedia, lab and classroom applications, this system includes one wireless transmitter, twelve headphones and a lockable carrying case (lock not included). Easily switch between 4 different frequencies with color-coded switches. Add additional transmitters to have up to 4 different channels of audio simultaneously!This 12-Person BluetoothÂ® Wireless Listening Center Includes:(1) BluetoothÂ® Wireless Transmitter (W900-BLTM)(12) Wireless Multi-Channeled Headphones (W901-Multi)(2) AC Power Adapter (W980) for use with transmitter and headphone charging (NOTE: A single AC power adapter is only capable of charging 6 wireless headphones at one time. Do not combine two 6-way charging cables with one AC power adapter).(2) 6-way charging cables (W990) for wireless headphone charging(1) lockable carrying case (lock not included) Optional Accessories (Not Included):HygenX45- Disposable sanitary ear cushion covers (box of 50 pairs).Portable Automatic Headphone Sanitizer (HygenX4-MIN) - Patent pending sanitizer ÂÂ developed and built by HamiltonBuhl ÂÂ automatically and safely sanitizes headphones and other small electronic devices with UVC light irradiation.