The SD37 is a UL555S Classified Leakage Class I smoke damper. It features:
- UL555S Class I.
- Rated to 2,000 fpm and 4" w.g.
- With factory furnished actuator, provides fail-safe operation (the damper automatically goes to the desired fail-safe position when fire interrupts power.)
- Available with factory furnished sleeves.
- Galvanized steel construction.
