steel, fire rated access door for walls & ceilings. With an insulated door panel, this unit has a ul 90-minute label for walls with a maximum temperature rise of 250 degrees after 30 minutes. This unit is also test up to 3 hours in ceiling applications and carries a warnock hersey rating for ceilings. self latching, 1 latch. White finish. 18″w x 18″h outside flange dimensions. 16-1/8″w x 2-9/16″d x 16-1/8″h return flange dimensions.