The CG125 piston ring is a key sealing component of a single-cylinder four-stroke pushrod engine, working in conjunction with the piston and cylinder. It consists of two compression rings and one combined oil ring, responsible for sealing the cylinder, controlling engine oil, and conducting heat. It is compatible with the CG125 and other 125cc platform motorcycles. The two compression rings work together to prevent high-pressure gases in the combustion chamber from leaking into the crankcase, ensuring the compression ratio and power output. The combined oil ring scrapes excess oil off the cylinder wall on the downward stroke and distributes oil to form a film on the upward stroke, reducing wear and oil consumption. The compression rings conduct heat from the piston to the cylinder wall for dissipation through the air-cooling system, preventing the piston from overheating and deforming.