Uses Model J Fusible Link, a quick response standard fusible link
More consistent release temperatures compared to resetable bi-metal product
No external load on link, regardless of fire/smoke damper size
Faster response time by positioning fusible link in air-flow
Load applied on fusible link is part of EFL assembly
EFL uses a S.P.D.T. switch for wiring a smoke detector. Upon smoke detector activation, the switch bypasses the fusible link and closes the damper, and remains closed until smoke signal stops. Listed by Underwriters Laboratories, Inc.