Sliders
A slider is a horizontal track — appearing as a set of discrete steps or as a continuous bar — that represents a finite range of values. People can tap buttons on the sides of the slider to increase or decrease its value by a predefined amount.
If necessary, create custom glyphs to communicate what the slider does. The system displays plus and minus signs by default.
For developer guidance, see Slider (SwiftUI) and WKInterfaceSlider (WatchKit).