Polk Audio 900-LS In-Ceiling / In-Wall Speaker System Package This Package includes (2) Polk 900-LS Speakers, (2) Polk 265-LS Speakers & (1) Polk 255 CLS Center Channel Speaker 900LS: frequency response 40-29,000 Hz (-3dB), handles up to 150 watts, sensitivity 90 dB, dual-port bandpass enclosure for better bass response 265LS: 1" ring radiator tweeter 6-1/2" Dynamic Balance midrange 6-1/2" Dynamic Balance woofer, handles up to 200 watts,sensitivity 91 dB Polk 255CLS: frequency response 44-29,000 Hz (-3dB), 1" Dynamic Balance ring radiator tweeter dual 5-1/4" Dynamic Balance woofers, handles up to 150 watts sensitivity 91 dB