• Compatible piston diameter: 90mm (3.56 inches) • Includes 2 balance rings and 1 high-quality seal ring • Seals the combustion chamber and channels the piston heat to the cylinder • Improves compressor performance and reduces oil consumption • Outer ring diameter: 95mm (3.74 inches) • Balance ring thickness: 3mm (0.12 inches) • Seal ring thickness: 4.5mm (0.18 inches) • Color: Black • Note: Turn off the air compressor and relieve pressure before changing the piston rings