Copying attributes
The Attribute Dropper tool lets you
copy the fill, stroke, and effect attributes from one object in your document to
another. In effect, this copies all of the formatting you can set in the
Properties panel in one movement. To copy these attributes from one object to
another, click the fill or stroke area of the first object, then, while you hold
down the mouse button, drag the Attribute Dropper tool to the second
object. Release the mouse button over the fill or stroke area of the second
object. If the second object has no fill or stroke color, then release the
mouse button while the tool is over the path itself.
Dragging the Attribute Dropper from the object on the left to the object on the right copies the fill, stroke, and live effects (in this case, a Gaussian Blur) to the second object.