20 in. Round Automatic Damper. Overview Honeywell Automatic Round Damper power-close, spring-open models ensure low leakage while controlling circulating air in heating, cooling and ventilation systems. Features Features glavanized steel with single-blade damper, which closes off tightly against gasket for minimal leakage Designated as power closed/spring return open damper for use with Honeywell Zoning Systems Can be field-converted when used as an independent zone or for fresh air intake Rated to operate up to 1-inch wc Available in 5- to 10-inch, 12-, 14-, 16-, and 18-inch diameter sizes Product Specifications Application Zone Damper Item Type Product Voltage 24V Size (in.) 20 in. Shape Round Motor or Actuator Mounting Side or Top Motor Power closed, spring open, reversible Motor Timing 30 seconds power open/10 seconds spring return Wires to Motor 2 Other Motor Information Range stops