Is Slider Range
Enable if the selected Part represents the Sliders operating range.
Is Slider
Enable if the selected Part represents the Slider (the Part that actually moves along the Slider Range). This option is not available on Parts on the Background.
Slider Range
This option is available when the slider is fitted into a Module. It indicates what values the slider should generate. The Axis option is standard flight sim Axis values, whilst Custom allows the specification of a Min Value and Max Value.