These are a NOS set of leaf spring inserts pads or spring insert silencers.  These pads are made for 1955-1957 Chevrolet vehicles.  They're made with a cotton material and fused with a hard wax.  The pads you see pictured are the pads you will receive.  Look closely to ensure you have the right part.  This box came out of a parts bin, and the four brown pads might be for a different year vehicle.