The Gen IV uses an exclusive fully electronic microprocessor control system that eliminates cables or vacuum connections. Separate high-capacity copper parallel-flow heat coil and aluminum plate-and fin-cooling coils provide outstanding performance and instant temperature adjustments. Additional features include variable blower speed and dash/floor/defrost blend.This kit fits 1964-66 Chevrolet Pickups and Suburbans without factory air, and adapts your OEM rotary control panel to electronic operation using our patented Electronic Cable Converters.