System.Object
   System.Collections.ObjectModel.Collection<T>
      System.Collections.ObjectModel.ObservableCollection<T>
         C1.Xamarin.Forms.Gauge.GaugeRangeCollection
   System.EventArgs
      C1.Xamarin.Forms.Gauge.GaugeValueEventArgs
   Xamarin.Forms.BindableObject
      C1.Xamarin.Forms.Gauge.GaugeRange
      Xamarin.Forms.Element
         Xamarin.Forms.VisualElement
            Xamarin.Forms.View
               C1.Xamarin.Forms.Gauge.C1Gauge
                  C1.Xamarin.Forms.Gauge.C1LinearGauge
                     C1.Xamarin.Forms.Gauge.C1BulletGraph
                  C1.Xamarin.Forms.Gauge.C1RadialGauge

Reference

C1.Xamarin.Forms.Gauge Assembly