There are two indicators in this product. One will draw historical lines based on high and low prices and the other uses open and close prices. The user can customise the line colour and style and the timeframe for the lines - daily, weekly or monthly. The lines are drawn on the right hand side of your price chart to keep your chart uncluttered and clean.
 
The field marked Limit refers to the number of lines for the chosen timeframe. Remember there are 250 trading days in the year so if you choose the 1 Day timeframe and limit = 250 you'll see one year's worth of daily lines.
 
You can add multiple instances of this indicator to your price chart so you can have one drawing Weekly lines and another drawing Monthly lines. Typically I will change the line style (solid, dash, dot) to denote a different timeframe. That way I can see which price levels are more important.