Nailor D1200 and D1200-3 Series Airfoil Multi-blade Fire Dampers provide the ultimate in fire containment for both static and dynamic HVAC systems. The design utilizes an innovative inter-locking double skin airfoil blade that maintains a complete barrier throughout the fire test with absolutely no visible through-gaps. Amazingly, the damper gets tighter as it gets hotter! Ideal for use where building codes require a fire damper for the protection of ductwork penetrations in walls or floors with a low pressure drop design suitable for high velocity applications. Premium performance, versatility and assured closure under airflow make the D1200 and D1200-3 series dampers an excellent choice for the majority of today’s commercial applications.