【Quality Material】The switch is constructed with a black finish, providing durability and resistance to wear and tear in industrial environments. 【4 Position Control】The rotary switch has four distinct settings, allowing for precise control of your heater or blower fan. 【3 Speed Control】Three of the positions are designed for speed control, giving you the flexibility to adjust the output of your heating or ventilation system to meet needs. 【Easy to use】The rotary design makes it easy to adjust the switch, even with gloves on. 【Industrial Use】This switch is designed for use in industrial settings, where it can withstand the demands of constant use and exposure to dust, dirt, and other contaminants. Black Rotary Switch 4 Position 3 Speed Heater Blower Fan Switch Control Knob, Industrial Switches, Push button Rotary Switches