The flap arm covers are designed to cover the moving steel parts of the flap actuating tubes in the rear seat of the RV-4 and Rockets. These moving parts are a hazard to your expensive headset cables and other items that may be in the rear cockpit.
Want to see a grown man cry? Just cut the cable on his new $750 headset.
They can also prevent loose items from jamming your flap actuators while you’re concentrating on your approach to landing, a real safety enhancement!