Piston Rings Std / Husqvarna 503 28 90-24Pack Size:1Husqvarna 503 28 90-24Husqvarna K950 cut-off saws, K950 ring and K950 chainsawsCylinder Diameter: 56 mm, Ethanol: Not compatible with greater than 10% ethanol fuel, Packaged in reusable protective polycarbonate case