2U standard 19-inch rack-mount amplifier. Connects automatically to server once there is network. Support wired network and WIFI wireless internet access modes. Automatic synchronization between timing program of terminal and the server. Works online and offline. Models in 60W/ 120W/ 240W/ 350W/ 500W (70V / 100V and 8ohm) power amplifiers. 2 line inputs (AUX) 3 Microphone input and 1 Line Output. Playback of MP3 programme or pre-recorded messages on server. Remote programme selection and volume control.