The MTD KM-13008-6058 Lawn Mower Ring Set Piston helps maintain proper cylinder sealing and engine compression for reliable performance. This replacement piston ring set fits around the piston and works against the cylinder wall to help seal combustion pressure while controlling oil movement within the engine. Properly functioning rings support efficient combustion, steady power deliv... https://www.wholetoolbox.com/mtd-km-13008-6058-lawn-mower-ring-set-piston/KM-13008-6058.html