Graded Valve Tappet, 4.000, Part 5139458-400 is a critical component of the engine. It is designed and tested by Polaris Engineers to ensure durability, quality, and optimal performance through lab and field validation testing beyond the expected engine life. Spend less time doing tedious maintenance and more time out on the trails having fun. We''ve been a leader in the powersport industry for nearly 70 years, don''t settle for anything less than OEM quality. This Accessory is Designed to Fit the Following: 2019 Ranger 500 --, 2019 Ranger 500 --, 2019 Sportsman 450 HO, 2019 Sportsman 450 HO, 2018 Sportsman 450 HO, 2018 Ranger 500 --, 2018 Ranger 500 --, 2017 Ranger 500 2x4, 2017 Ranger 500 2x4, 2020 SPORTSMAN 450 HO , 2020 RANGER 1000 FULLSIZE PS FO , 2020 SPORTSMAN 450 HO EPS , 2020 RANGER 1000 CREW FULLSIZE PS FO , 2020 RANGER 1000 PS CREW FS , 2020 Polaris Pro XD , 2020 SPORTSMAN 450 HO UTILITY , 2020 Polaris Pro XD Crew , 2020 RANGER 500 HDPE ISRL , 2020 RANGER 1000 FS , 2021 RANGER 500 , 2021 RANGER 500 , 2021 RANGER 1000 FULL SIZE , 2021 RANGER 1000 PS CREW , 2021 RANGER 1000 PS CREW EVAP , 2021 RANGER 1000 PS FULL SIZE , 2021 RANGER 1000XP PS CREW , 2021 SPORTSMAN 450 HO , 2021 SPORTSMAN 450 HO EPS , 2021 SPORTSMAN 450 HO UTILITY , 2021 R21RM250A1 RANGER 500 2WD , 2021 RANGER 1000 FULL SIZE EPS EU TRACTOR ZUG , 2021 RANGER 1000 FULL SIZE IS EU , 2021 R21MAA50J7 RANGER 500 IS , 2021 Polaris Pro XD , 2021 Polaris Pro XD Crew , 2021 RANGER CREW 1000 PS , 2021 RANGER CREW 1000 PS EVAP , 2021 RANGER CREW XP 1000 PS ,