Replacement piston kits for M-Spec big bore cylinder 4-stroke pistons are made using a double-bridged forging design Lightweight pistons with the tightest piston-wall clearances in the industry give you a quieter running engine Made in the USA - Polaris RZR 570 4x4 (2017, 2012, 2013, 2015, 2016, 2018, 2019, 2014); Polaris Sportsman Touring 570 4x4 (2019, 2016, 2018, 2015, 2017); Polaris Ranger 570 (Mid-Size) EFI (2018, 2019, 2017, 2016, 2015, 2014); Polaris Ranger Crew 570 4x4 (2014, 2018, 2016, 2015, 2017, 2019); Polaris Sportsman 570 EFI 4x4 (2014, 2019, 2015, 2017, 2018, 2016); Polaris Ace 570 4x4 (2016, 2015, 2017); Polaris Sportsman X2 570 EPS 4x4 (2016, 2017, 2019, 2015, 2018)