Linear Gauges are supposed to imitate real gauges that measure a single value - like thermometers measure temperature. It is evident that such a gauge has no need in complicated charting elements, though, they might be added in some cases.
There are four linear pointers, two of them are of bar pointer type and another pair is of LED pointer type. All four pointers imitate battery chargers with different charge level: 5%, 75%, 20% and 100%. This chart is built as the Table Layout. There are neither legend nor labels on the chart, but there are titles with the pointer types defined and the chart title. Tooltips display the main information about the pointer - the battery charge level.