Cat® Rings are important components of pistons, that fit into a groove on the outer diameter of the piston body between the top ring and the oil ring. Piston rings function is to form a seal between the piston head and the cylinder wall that prevents the loss of combustion cylinder gases to the crank case, maintains a constant level of lubricating oil between the cylinder wall and the piston and regulates engine oil consumption by scraping oil from the cylinder wall back to the sump.Application:Consult your owner's manual or contact your local Cat® Dealer for more information.