This is an OEM part sourced directly from the manufacturer. The ring is found in Rolair compressors and pumps. This part is made of metal and is used in the connection between piston and cylinder. Please be aware that there are different rings used in the machine. Refer to the parts diagram to be sure of ordering the correct part. Yo...Read moreu may require a screwdriver and wrench when replacing this item. This part is sold individually.