Horizontal lines are often used to make a note of a specific price. They can also be very useful when marking off levels of support and resistance. Much like X-Lines (which may be drawn in any direction), Horizontal Lines continue on in their respective direction indefinitely.
In Style property dialog it is possible to change the appearance of the Horizontal Line:
Can change the color, opacity and thickness of the Horizontal Line as well as the line style.
When Show Text checkbox is active, a text for displaying beside the Horizontal Line may be entered in the text box. Text color and opacity, font size, bold and italic attribute may be assigned in the drop-downs next to the checkbox. Text Alignment drop-downs allow to set the text position along the Horizontal Ray.
In Shape properties dialog, you can set precisely the position of the Horizontal Line by setting it’s initial point’s position on the price scale (by setting the price) and the time scale (by setting the bar number):
In View properties dialog you can switch displaying of a Horizontal Line on charts of different timeframes: