Polk Audio Monitor 40 AM4025-A 2-Way Bookshelf Speakers (Pair, Black) Built-in keyhole wall mounting brackets provides secure on-wall mounting All MDF construction and extensive cabinet bracing ensure resonance-free enclosures Equipped with dual 5.25-inch bi-laminate composite dynamic-balance drivers Pair of bookshelf 2-way speakers that delivers superior linearity, definition and sound imaging Equipped with one 1-inch silk polymer-composite dynamic-balance dome tweeter Pair of bookshelf 2-way speakers that delivers superior linearity, definition and sound imaging Equipped with dual 5.25-inch bi-laminate composite dynamic-balance drivers Equipped with one 1-inch silk polymer-composite dynamic-balance dome tweeter All MDF construction and extensive cabinet bracing ensure resonance-free enclosures Built-in keyhole wall mounting brackets provides secure on-wall mounting