These LED signal towers are marketed as andon lights, which have a fairly long tradition in modern manufacturing. 'Andon' is borrowed from the Japanese term for "lantern," and these devices are used to visually communicate changes in the production process or a change in quality.
When an andon light comes on, depending on its color symbol (when more colored lights are used in conjunction with one particular process), it signals to workers to tend to the quality or process change.
These andon lights kits come in handy because of their relative simplicity, and their ability to be seen from a distance and attract the eye -- especially in places where noise is high and other signals might not be noticed. Depending on the color that displays, workers can immediately rectify the problem and get the production line moving again.
Our current inventory of andon lights are great for lean manufacturing, especially jidoka systems, and our products are made with LEDs to maximize cost savings and power conservation over typical incandescent bulbs.