Antique Singer Treadle Sewing Machine Belt Guide and Mounting Bolt.   This is the part which guides the drive belt at the fly wheel.

Photo is representative of the 2 guides offered.  You are purchasing one.     

These are original Singer parts, with antique patina just as removed from the machines.   These are entirely serviceable and can be cleaned and/or restored to whatever level the new owner chooses.  Expect some surface rust, etc. as shown.  Original antique Singer part.