A fire damper for an air distribution system includes a body defining a flow path and a closure means adapted to close the flow path when a temperature within the flow path exceeds a predetermined maximum temperature. A first flange is fixed to the body and a mounting means comprising a second flange is slidably engageable with and removable from the body. The mounting means comprises securing means for securing the mounting means to the body such that a building element through which the fire damper extends, in use, can be clamped between the first and second flanges. A flexible insulating sleeve configured for use with a fire damper, and a method of installing a fire damper, are also disclosed.