Definitive Technology ProMonitor 1000 Bookshelf Speaker (Single, White) Single ProMonitor bookshelf speaker Equipped with one 5.25-inch cast basket bass/midrange drivers coupled to one 5.25-inch pressure-driven planar low-frequency radiators Frequency response: 47Hz - 30kHz Equipped with one 1-inch pure aluminum dome tweeter The high quality finish is available in gloss black or gloss white