Abstract: A fire-damper has a support adapted to be secured in the duct and having a pair of pivots defining respective parallel and spaced-apart pivot axes traversing the duct. Respective damper flaps are pivotal on the pivots about the respective axes between an open position extending generally parallel to and spaced from each other in line with the duct and a closed position generally coplanar transverse to the duct. Thus the flaps define in the open position open flow spaces between and to both sides of the flaps and in the closed position the flaps substantially block flow through the duct. A spring urges the damper flaps continuously into the closed position. A fusible link is connected between the flaps offset from the axes for retaining the flaps in the open position unless the link is heated beyond a predetermined temperature. This link extends across the flow space formed between the two flaps.