Robot Servos are the muscles of your robot and come in many different shapes, sizes, and strengths. Hobby Servos are classic PWM controlled actuators used primarily in R/C applications but have found their way into mainstream hobby robotics over the years due to their low cost and ease of use. As technology progressed, a 2nd generation of Robot Servos emerged; utilizing metal gear trains, advanced feedback capabilities, and high-speed data communications, making them ideal for higher end robotics projects.