Piston Rings Std / Husqvarna 522 99 01-01Pack Size:1Husqvarna 522 99 01-01, Husqvarna 503 28 90-47HL Supply H05112Husqvarna 570, 575 XP, 579 XP chain saws; K 750, K 760 cutoff sawsCylinder Diameter: 51 mm, Ethanol: Not compatible with greater than 10% ethanol fuel, Packaged in reusable protective polycarbonate case