Definitive Technology ProMonitor 1000 Bookshelf Speaker - Single, Black (Certified Refurbished) This Certified Refurbished product is tested & certified to look and work likenew. The product includes all original accessories, and is backed by a 1 year warranty. Sonically, the ProMonitor 1000 satellite is a revelation in terms of achieving incredible sound at an affordable price. 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: 47 Hz to 30 kHz  Recommended amplification: 10 to 200 watts  Efficiency: 90 dB Dimensions: 6.25 by 10.88 by 6.5 inches (W x H x D)  Magnetic shielding: Yes  Finish: Gloss black