The Efco 0054139 genuine cylinder kit is a high-quality replacement component designed for Efco 137 and 140 chainsaws, as well as Oleo-Mac GS 370 and GS 410 models. This kit features a 40mm bore and includes the cylinder, piston, piston rings, piston pin, and circlips, ensuring optimal engine performance and longevity. It directly replaces the older part number 58070200A, providing a perfect fit and reliable operation for your outdoor power equipment.