Piston Kit Pro-Lite SeriesDesigned for all-purpose 2-stroke ridingDurability, longevity and increased horsepowerDedicated forging design for strength-to-weight optimizationExtra lightening operations for enhanced throttle responseEngineered, forged, and machined in the USAPiston is made in the USA'84-'86 Polaris Indy Trail 440, '85-'86 SS 440, '87 Long Track Reverse 440, '84-'90 Long Track 440, '93 Indy Trail 440, '94-'97 Indy Super Sport 440, '97-'98 Indy XCF, '95-'99 Indy 440 Sport Touring, and '96-'99 Indy Transport bore oversize is +1.53 mm. Other models listed the bore oversize is +2.03 mm.