They are designed for all out racing, with heavy duty suspensions, oversized shocks and big tires that enable them to survive the roughest conditions. They can move up hills, down slopes, and even over other cars. ARR stands for Almost Ready-To-Run, while RTR is Ready-to-Run, usually identical to the former but with a radio system.When starting a new hobby, it is certainly important for one to become familiar with the terms often used in that field. Chassis - This is the framework on which the components of a truck are mounted. ESCs increase power efficiency and precision, while reducing a model's weight for better performance. The word chassis is also sometimes used to refer to an entire vehicle, excluding the body, wheels, and tires. Throttle - To increase or decrease acceleration, manipulate the throttle. It is the one that changes the voltage going to the truck's motor or the fuel/air mix going to the engine. Electric starters are generally designed for airplane engines and require an adapter to work with truck engines. China Pedelecs Factory Electric starter - A hand-held electric motor used for starting a model engine, usually powered by a 12-volt battery. ARR/RTR - Some remote control trucks are almost completely assembled in the factory. Of course, the world of remote control trucks is no exception; it also has a language of its own. ARR and RTR trucks cost a little more than unassembled models, but are practically ready to run right out of the box. Electronic Speed Control (ESC) - This replaces the mechanical speed control and servo usually found in 'entry-level' electric remote control trucks. Stadium truck - Remote control stadium trucks, like their full-size counterparts, are built to take punishment. Servo - The electromechanical device which moves the control surfaces or throttle of the truck according to commands from the receiver. They 'tie' these two parts together. It can be made of sturdy composites, aluminum, or graphite. Monster truck - Monster trucks are big and designed for torque instead of speed. Tie rods - Tie rods provide steering control by attaching the steering servo to the front wheels.