NHT Classic Two Bookshelf Speaker (Black, Single) Frequency Response 51Hz-20kHz / Sensitivity 86dB (2.83v@1m) / Impedance 6 ohms Nominal/ Maximum 150 watts Dimensions (WxHxD) - 7 x 12.125 x 8.875 inches (178mm x 308m x 226mm) / Weight 12.7 lbs./5.8 kg High Gloss Black Piano Finish Sold as Single Speaker, Two Required To Make a Pair