Here is a complete listing of the example source file.
import QtQuick 2.11
import QtQuick.Controls 2.1
import QtQuick.Layouts 1.3
 
 
ElementSettings {
    element: pump
 
    property Pump pump
 
 
    GroupBox {
        title: qsTr("Custom properties")
 
        Layout.fillWidth: true
 
        GridLayout {
            columns: 2
 
            Label {
                text: qsTr("RPM:")
            }
 
            Slider {
                from: 0
                to: 120
 
                value: pump.implicitRpm
 
                onValueChanged: pump.implicitRpm = value
            }
        }
    }
}