Polk Audio V60 High Performance Vanishing in-Ceiling Speaker (Single) Polk's wafer-thin Sheer-GrilleTM with ultra-small .6mm perf attaches magnetically to fit flush (acoustically inert). Swivel mount high-performance " aimable silk dome tweeter for crisp, clear imaging. 6 " Dynamic Balance polypropylene cones deliver spectacular midrange clarity, punchy bass and high efficiency. Polk patented Rotating Cam System ensures secure,vibration-free installation. Great height effect speakers in Dolby Atmos installations.