These are new, U.S. Made, decorative Lyre pendulum replacement bobs. This is a replacement for a 10-1/2″ Grandfather clock lyre pendulum bob but the overall diameter is actually 10-7/8″ (this will not affect timekeeping). It has a nice polished brass finish with a 1-13/16″ wide plain edge and a 7″ molded convex glass center.
Some lyre pendulums have a nice decorative “harp” piece that rests on top of the bob and is riveted or screwed to it. You would need to remove the rivets to separate it from the bob. There are two holes on the back of this bob to reattach it, if necessary. The metal center rod on your pendulum should then slide through the slots on the back of the bob and then you can screw on your rating nut.