The adjustment property of type gtk:adjustment (Read / Write)
The adjustment that contains the current value of the scale button.

The icons property of type g:strv-t (Read / Write)
The names of the icons to be used by the scale button. The first item in the list will be used in the button when the current value is the lowest value, the second item for the highest value. All the subsequent icons will be used for all the other values, spread evenly over the range of values. If there is only one icon name in the icons list, it will be used for all the values. If only two icon names are in the icons array, the first one will be used for the bottom 50% of the scale, and the second one for the top 50%. It is recommended to use at least 3 icons so that the scale button reflects the current value of the scale better for the users.

The size property of type gtk:icon-size (Read / Write)
The icon size.
Default value: :small-toolbar

The value property of type :double (Read / Write)
The value of the scale.
Default value: 0