System Features GEN II® Heater with Defrost and Servo Door ControlNew design provides superior performance from servo-motor-controlled air door, improved case design, and our exclusive electronic servo-actuated heater control valve. New 3-knob control operates temp, fan speed, and heat/defrost balance. Includes: GEN II® heater with defrost and servo door control, 3-knob control panel (knobs can be mounted directly into dash), universal defrost ducts (may also be used with optional dash louvers), and an electronic servo heater control valve. Instructions Installation Instructions download Vehicle Fitment warning California Proposition 65 arrow_drop_down WARNING: California proposition 65