Definitive Technology UIW55 Rectangular In-Wall Speakers (Pair, White) Pair of in-wall/in-ceiling rectangular 2-way loudspeakers Equipped with one 5.25-inch cast-basket bass/midrange driver Frequency response: 35Hz - 30kHz Equipped with one 1-inch pure aluminum dome tweeter in a D'Appolito array Cut-out size: 5.5 W x 9.25 H inches