Polk Audio 255C-RT In-wall / In-ceiling center channel speaker Vanishing Series in-wall center channel speaker, built-in speakers feature our exclusive wafer-thin Sheer-Grille, a magnetically-secured grille that protrudes only 7mm from its surroundings, have the centerpiece of a world-class stealth home theater In-Wall:Mount clearnace required for mounting Dogs (add to each side of cutout)3.375 inch (8.57 cm).Dual band pass bass ports are highly efficient in small enclosures, and smoothly funnels the angled woofer's low frequencies down around the driver array Compatible with Polk Audio RTi speakers, recommended Amplifier power per channel 10 to 150 watts.Grille Dimensions 9.31 H x 14.81 W (inches). Clearnace Required for Mounting Dogs (add to each side of cutout) 3.375 inches Easy one-cut, drop-in installation puts built-in audio within reach, with Perfect Fit templates, a precision flange; achieve secure, vibration-free efficiency with a simple turn of the patented Rotating Cam system Dimension(inches):7.625 h x 13.125 w. Total Frequency Response is 30 Hz to 27,000 Hz