The Sensata L411F is a line-level fan speed controller that uses Pulse Width Modulation (PWM) to regulate the output speed of a fan. It supports 4 types of input signals, namely 4-20mA, 0-10V, 0-5V, and PWM, and can deliver output of 0-10V, 0-5V, PWM, or 3-wire series voltage signals. It also features adjustable parameters such as a speed range, minimum and maximum speed setting, overspeed protection (auto shut-off), and an external speed control input. The L411F is suitable for a variety of industrial and commercial applications, such as ventilation systems, HVAC, and computer servers.