42" Fireplace Glass Door Set To Fit Heatilator Unit Fits A42C, A42R Please Do Not Order Unless Your Model Matches One Listed. These doors will not fit your unit unless you have one of the models listed. Sometimes A Tag Containing Model#, Make, Date Of Manufacture Can Sometimes Be Found On Inside Sheet Metal Wall Of Firebox. Inside Frame Measurement Requirement: Width: 42" Height: 23-1/2" to 24" Available In 2 Finishes (Black or Silver)