Key Benefits Direct Retrofit Compatibility: Specifically designed to convert T-400 series dual-temp thermostats to T-4000 series without replacing the original Bakelite back

it serves as a direct drop-in for 440V and 370V systems

optimizing the system's SEER performance and preserving indoor air quality for occupants

which is critical in applications where a damper must remain partially open to ensure a minimum percentage of air circulation even when the controller signal is at zero

pre-stripped leads and a terminal board for quick low-voltage terminations

ZoneFirst SPRD-12X12 Damper Els PW 17895 Key Benefits Direct Retrofit Compatibility:The ZoneFirst SPRD 12X12 is a professional grade barometric static pressure regulating damper engineered to maintain system integrity in multi zone residential and commercial HVAC applications. Built from heavy duty 22 gauge galvanized steel, this 12" x 12" rectangular bypass damper utilizes a counter balanced weighted arm to automatically relieve excess static pressure as zone dampers close. By bleeding off excess air, it prevents evaporator coil