This is an antique cast iron sash pulley with scalloped edges. The weights and pulley counter balance system was one of the great achievements in window development, it was used in fine homes before the nineteenth century and in common homes after the civil war per Steve Jordan's The window sash bible: A guide to maintaining and restoring old wood Windows. There is some paint on these pulleys as it was typical to paint cast iron hardware at the time.

From an 1880 catalog of hardware: Mortising for this Pulley is all done with a bit, no chisels required. A central bit for hand boring and an augur bit for machine boring, are the only tools needed. Bore the three centre holes through, and the two end holes 1/8 inch deep, which will let the face of the Pulley in flush with Jamb (the holes left by centre of bit are intended to receive screws for the Pulley and a mortise is produced exactly fitting the face of Pulley. Dies are furnished free for marking hole centres. It will thus be readily seen that this is the fastest applied Pulley in the market, by eight to one by hand, twelve to one by machine.