The plastic access panel is designed to provide easy access to walls & ceilings. The high impact styrene plastic with U.V. stabilizers will not fade or corrode. All units except the 14×29 are hinged with a removable door panel feature. White Finish. 17″W x 17″H Outside Flange Dimensions. 14″W x 3/4″D x 14″H Return Flange Dimensions.