The Subaru / Robin 279-23511-17 Piston Ring Set provides the sealing components needed for compatible small engine pistons. The piston rings help maintain cylinder compression and control oil movement between the piston and cylinder wall during engine operation. This replacement set is designed to replace worn or damaged piston rings during engine repair and maintenance. Proper instal... https://www.wholetoolbox.com/subaru-robin-279-23511-17-piston-ring-set/279-23511-17.html