Almost Ready-to-Fly (ARF) remote control airplanes come pre-covered and mostly built. Assembly time is minimal and requires the installation of servos, power system, and radio system. ARF models include various historical and legendary planes, which can come to life with the realistic sound of either a gas or nitro engine power plant. Alternatively electric power systems can be fitted. ARF models DO NOT include any electronic components or power systems and are generally sold as an airframe only. Check the airplane's product page for additional requirements.