The SSD-RD series are UL, ULC and California State Fire Marshal listed as a UL555S smoke damper. This True Round damper is available in either UL555S Class I or Class II leakage ratings, and can be provided with a wide variety of electric and pneumatic actuators
Available with either UL Class I or Class II leakage.
Available for both vertical and horizontal mount.
Available with 16" (standard), 20" or 24" deep frames/sleeves.
Available with 24VAC, 120VAC or 230VAC electric actuators or Pneumatic actuators