Piston Rings Std / Husqvarna 503 28 90-35Pack Size:1Husqvarna 503 28 90-35Ahlborn FOR-6345Husqvarna 394, 395 chain saws; K960 and K970 cutoff sawsCylinder Diameter: 56 mm, Ethanol: Not compatible with greater than 10% ethanol fuel, Packaged in reusable protective polycarbonate case