The Functional Devices RIBU1C SPDT Relay is a compact, versatile switching device used to control electrical loads in HVAC systems. It operates by receiving a control voltage that actuates a single-pole, double-throw (SPDT) contact, enabling switching between two circuits. Commonly applied in air handlers, fan coils, compressors, and lighting control, it ensures dependable performance and control flexibility. Its compact design supports easy installation in tight spaces. The relay enhances system efficiency, reduces wiring complexity, and provides reliable operation, making it suitable for both commercial and residential HVAC applications.