Polk Audio RTi4 High Performance Bookshelf/On-Wall Speakers (Pair, Cherry) Pair of real wood bookshelf or on-wall speakers with all MDF construction and resonance-free enclosures Equipped with a 5.25-inch polymer composite cone driver with rubber surrounds Features a neodynium magnet and a heat sink on the back of the magnet Equipped with one 1-inch silk/polymer composite dome tweeter The PowerPort vent doubles as a strong, built-in wall-mounting bracket for easy, safe placement