Radius Marker for the Area of Effect Unit Trait

I guess I’m having difficulty understanding the use of the Radius Marker for the Area of Effect unit trait.

What qualifies as a marker?

For the unit I’ve created a Marker and assigned a numeric value and a Dynamic Property with a numeric value and neither one seem to create a radius of greater than zero. The hex the unit is in will be shaded and nothing more. This is for a map with a hex grid.

Never mind. I figured it out. I was using the value $marker$ instead of the name marker.