Patent Number 5819804

• Flexible 24 in steel cables will slide through elbows and are interchangeable with the handle to fit different size copper Durable polypropylene handle will fit 1/2 in thru 2 in cables Long-lasting elastomeric plug Eliminates "bread" and outperforms all the rest Fits through 90 deg elbows

The DuroZone® multi-blade damper for residential zoning systems has been engineered to include many features. Ribbed for strength and extruded from lightweight aluminum, the sleek frame profile provides maximum strength without excessive reduction of free-area inside the ductwork. The extruded aluminum blades are mounted with friction minimizing nylon bushings to provide easy transition between opening and closing. The DuroZone® spring return multi-blade dampers also feature damper blades designed to remain within the damper frame for easy insertion and an external side-mounted linkage for smooth and quiet operation. Multi-blade dampers with a 24 V spring return mid torque motor.