This checkpoint indicator is a visual wear marker for threaded fasteners. It is installed on a bolt or nut head and provides a clear, at-a-glance indication that the fastener has been loosened or tampered with. The indicator works by breaking or shifting its visible element when the fastener is rotated, allowing an operator to identify a loosened connection without a torque check. It is used on assemblies where maintaining a specific clamp load is critical. On installation, the indicator must be fitted to a clean, dry fastener head and the fastener torqued to specification before the indicator is set.