Indicator status lights are devices used to signal the status or condition of a system, equipment or machine. They come in a variety of colors, shapes, and sizes and can be used to indicate on/off status, fault conditions, or to provide visual confirmation of machine or system operation. The colors used in indicator status lights are often standardized to indicate specific conditions, such as red for alarm or warning, green for normal operation, or yellow for caution or attention. Some indicator status lights use LED (Light Emitting Diode) technology for improved reliability and longer life. Indicator status lights are widely used in the semiconductor industry to monitor and control various stages of wafer processing and manufacturing.