Zonefirst SPRD-18 Damper 30067439-890 this specific model is rated

this specific model is rated for 120V/50-60Hz

While the diameter is 24 inches

is a rugged

For high-stakes commercial environments

and Miller B-Series air handlers without requiring cabinet modifications

Zonefirst SPRD-18 Damper 30067439-890 this specific model is ratedThe Zonefirst SPRD 18 is a professional grade 18 inch round barometric bypass damper engineered to maintain critical static pressure relief in multi zone HVAC applications. As zone dampers close, this single blade mechanical component automatically responds to rising pressure, diverting excess airflow to the return plenum or a dump zone to prevent coil icing and blower motor strain. Unlike motorized alternatives, the SPRD 18 utilizes a counter