Take your home theater to new heights These voice-matched height channel modules can be wall-mounted, or placed atop compatible Polk Audio Reserve Series speakers. They connect to your receivers "height" channels so you can experience overhead sound effects without having to install in-ceiling speakers. A home theater receiver with Dolby Atmos is required for operation. Polk Audio Reserve R900 speakers are compatible with the following speakers: Polk Audio Reserve R500 Polk Audio Reserve R600 Polk Audio Reserve R700 Polk Audio Reserve R100 Polk Audio Reserve R200