Includes 4 Polk Audio 80F/X-RT In-Ceiling 2-Way Round Surround Speakers. The Polk 80F/X-RT pair of in-ceiling surround-channel speakers fill your home theater with vibrant sound effects, while they are virtually indistinguishable from its surroundings. Each speaker is equipped with dual silk dome tweeters and a Dynamic Balance woofer that deliver incredibly detailed, clean sound with realistic imaging. Mounting the speakers is simple with a one-cut, drop-in installation and the rotating cam system secures them in place, ensuring vibration-free efficiency. They also feature a "Wall Distance" switch for flexible mounting that eliminates muddy bass response. Each speaker has a magnetic, acoustically inert, sheer-grille that provides dynamic, unimpeded sound and more uniform coverage, even in larger rooms.