This is a pair of replacement O.S. Engines Needle Valve O-Rings for the O.S. FS, FX, and LA series engines. This O-Ring can also be used for other applications where a 2.5x6mm silicone o-ring is needed.
NOTE: This part may be compatible with other O.S. engines. Please check your owner's manual and cross reference the part number to verify that this is the correct part for your engine.