This replaces the Afterburner toolhead with a dovetail mount for a dial test indicator (such as a Mitutoyo 513-404, which this was modelled on). The indicator point is ideally located at the same position as the nozzle (the precise Y position may vary depending on the length of the tip). There is a protrusion where the nozzle would be located, so that Z homing can be done normally as though a nozzle were present.
This can be used, for instance, to verify whether a mesh reflects the true form of the bed surface: sweeping the bed with the mesh enabled would ideally show no movement on the indicator.
