Cambridge SoundWorks 820 HD Radio [Black] Sleek enclosure design complements any decor Cambridge SoundWorks' custom-designed, high precision left and right speaker elements housed in a sturdy molded enclosure State-of-the-Art AM and FM tuner performance featuring iBiquity Digital Corporation's HD Radio technology Superior reception offered by unique-in-class telescoping antenna to support the FM band and an external AM loop antenna to support the AM band Rich, warm tone and clarity - Its clear sound at low volume is perfect for semi-enclosed spaces