Harold Beck & Sons 11-15X is a control drive designed to provide precise speed adjustment of conveyors and other machines. It features a compact design, easy installation and simple operation. The 11-15X offers a wide range of capabilities, including adjustable speed control using a potentiometer, a reversing switch, and overload protection. It can operate with either 115 or 230 volts AC power and is suitable for use with single-phase motors. Additionally, the 11-15X has a built-in thermal overload relay to protect the motor from damage in case of excessive heat.