Features on the flagship Performer Plus include: programmable CD player and digital functioning, built-in microphone records student progress on tape, headphone ports eliminates the need for a jackbox as well as variable speed CD/cassette playback (essential for language learning and dance /music classes too with 5 built-in 1/4" and a single headphone jack that eliminate the need for a jackbox)! With CD-R/CD-RW compatibility, Califone boomboxes can play CDs burned at school so students can record their work and you can keep it for their portfolios; CD player reads CD-R/RW files; tough ABS plastic exteriors withstand inevitable impacts; Dual cassettes record from CD and radio with “auto-stop” protection to help tapes last; Recessed speakers are loud enough for up to 100 students and covered by steel grilles to avoid tampering; Multiple inputs and outputs connect added microphones, external speakers and provide audio amplification from computers and other peripheral equipment; “Voice-Over” with a wired mic projects speech over any audio program for announcements and emergency response situations; Permanently attached three-wire cord for student safety; Full-feature remote control promotes flexibility and freedom of movement around the room; 14W RMS powerful enough for up to 100 students