This control allows to specify a subrange in predefined range easy using drag & drop. You also can use keyboard left and right arrows to increase and decrease value by one, PageUp and PageDown keys to decrease and increase value by TickInterval property value(or at least by 1), Home and End keys to set value to minimum and maximum. If you also hold Shift key a second tracker value will be changed instead of first. The same is correct for clicking on the control outside trackers: with Shift keyboard button pressed the second tracker will be changed, without Shift - the first one.

TrackRange widget