Husqvarna 181, 281, 288, 288XP Piston & Cylinder Assembly 54mm ,Replaces Husqvarna # 503506301 HUSQVARNA PISTON & CYLINDER ASSEMBLY , 503506301, 54mm High Quality suitable replacement cylinder rebuild kit. Includes cylinder, piston,piston pin, piston clips and required rings. Fits Husqvarna 181, 281, 288, 288XP (NOTE: 54mm Kit.)