Polk Audio TL2 Sat Speaker (Each, Black) .75" Silk-dome Tweeters 3.25" Composite Injection-molded Cones With Dynamic Balance Driver Technology Powerport 5-way Binding Posts Time Lens Technology Time Lens Technology-The acoustic centers of the tweeter and mid-bass driver are located in the same plane for superior imaging PowerPort a patented Polk technology, extends the low frequency mid-bass driver response as it decreases air turbulence, eliminates "port noise" and bass output losses up to 3 dB 3/4" Silk Dome Tweeters for crisp, clear imaging and smooth response that's never tiring 3 1/4" Composite Injection Molded Cones With Dynamic Balance Driver Technology Combination Keyhole Slot & 1/4" x 20 Threaded Insert fits all aftermarket ceiling and wall brackets for ultimate flexibility