The STIHL 11420302009 is an authentic OEM replacement piston designed for use in various STIHL MS 261 series chainsaws. This critical engine component reciprocates within the cylinder, converting the force of combustion into mechanical energy that drives the crankshaft. Made to STIHL's exacting standards, this genuine piston ensures proper fit, function, and durability, maintaining the chainsaw's power and efficiency. Replacing a worn or damaged piston with this original part restores engine performance and extends the life of your equipment.