(2) counterweights, part number 352117, Continental engine E-165, E-185, E-225, 470, 520 series. 

Please review your manual for your specific engine application.

The counterweights could be used in many homebuilt applications.  Applicable also to experimental airplanes, airboats.

email if you need additional pictures.  The counterweights were stored coated in heavy oil, tried to wipe for pictures.