When corridors or entrance ways occasionally need to be full width to allow the unimpeded flow of people or equipment but maintain the security of the double door opening, a 980 lockable mullion is ideal. Like the permanent version, the lockable mullion provides a solid and secure center point for the rim bolt to lock behind. When the need for additional width occurs, the head of the mullion is unlocked and the mullion is moved out of the way; then replace and relock when finished. No tools are needed, just the cylinder key. Designed for wide stile doors, in aluminum or fire rated steel, the 980 lockable mullion is the easy way to provide wide openings with a SARGENT exit device.