ArcGIS Pro 3.0 API Reference Guide
ArcGIS.Desktop.Core Namespace / VertexSymbolOptions Class / OutlineWidth Property

OutlineWidth Property
Gets and sets the outline width. Default value is 1.5.
Syntax
public double OutlineWidth {get; set;}
Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

ArcGIS Pro version: 2.9 or higher.
See Also