This is a new impellar part number 66886. 

This impeller is about 17" in diameter with a tapered shaft bore.

The fins are about 3" tall (from the top of the backing plate).

The backing plate is about 14.25" in diameter.

It is used on some Agri-fab Mow-n-vac Leaf catchers.

Please let us know if you have any further questions on this item!