Model PYF-SDc-K-W×HB / PYF-SDc-K-ΦB Smoke Exhaust Damper (Smoke Vent) is installed on smoke exhaust ducts and kept closed normally; upon fire alarm from smoke detectors, the control panel sends DC24V±2.4V electric signal to actuate the electromagnet for damper opening, and manual opening is also available. The damper can be manually reset after activation and outputs opening feedback signal to realize interlock with other devices, with full-open resistance coefficient less than 0.5, control voltage DC24V and operating current less than 0.7A.