Advent PMWTRIM Trim Kit for MW900B and MW912B Black Built-in Microwave Oven, Black, Outside Dimensions: 23.25W x 15H x 2.75D in. Inside Opening: 19W x 10.5H in. Box: 24 x 15.25 x 3.25 in. Trim Kit for MW900B and MW912B Built-in Microwave Oven, Black Made of Steel Outside Dimensions: 23.25W x 15H x 2.75D in. Inside Opening Dimensions: 19W x 10.5H in. Box Dimensions: 24 x 15.25 x 3.25 in.