The Polk Audio Signature Elite ES90 is a pair of Dolby Atmos-certified height module speakers designed to be placed on top of compatible Polk Signature Elite or older Signature series tower or bookshelf speakers. These modules add immersive, overhead sound for movies, music, and games by using upward-firing drivers to reflect sound off the ceiling. Key features include a 5.25-inch mica-fortified woofer, a 1-inch Terylene dome tweeter, and a secure rubber base for stable placement.