The Honda 13011-Z1C-800 Lawn Mower Engine Piston Ring Set supports proper sealing and compression within compatible mower engines. The piston rings fit around the piston and help seal the combustion chamber while controlling oil movement during engine operation. This replacement set is designed to replace worn or damaged piston rings during engine maintenance or repair. Proper install... https://www.wholetoolbox.com/honda-13011-z1c-800-lawn-mower-engine-piston-ring-set-0-25/13011-Z1C-800.html