This Genuine Tohatsu Marine Part is a piston ring set that is designed specifically for Tohatsu outboard motors. It is an oversized set with a 0.5 O/S measurement, indicating that it is slightly larger than the standard size. The part number for this set is 3FK-87124-0. These piston rings are essential components in the engine's combustion chamber, providing a tight seal between the piston and cylinder wall to optimize engine performance and prevent loss of compression. Made with high-quality materials, this Genuine Tohatsu Marine Part ensures durability and reliable operation for your Tohatsu outboard motor.