Select sharp edges what's the angle value in the manual

here is what is said about the "selecting sharp edges" command: 


  This tool selects all edges between two faces forming an angle greater
  than the angle value, Where an increasing angle selects sharper edges.


Ok, but what's the angle value then?

I tried to play with the angle value in the data tab of the properties editor (with autosmooth on), but it doesn't seem to affect my selection, so what is it? is it a fixed value internally coded?
You determine yourself the value on the bottom of the 3D view Tool panel (on the right of the 3D view, activated with T). Every edge with an angle above this one will be selected.