SPI, 09-718, (3) SPI Standard Bore Piston Kits Polaris Ultra SP 680 Pistons & Rings 66.6mm Manufactured by SPI Includes 3 pistons, ring sets, wrist pins, & circlips as pictured SPI pistons are engineered to provide the best possible path for combustion chamber heat transfer to the cylinder walls All SPI pistons, rings, pins, & circlips are manufactured to OEM specifications All individual components are interchangeable with original parts&gt;