These secondary clutch rollers are used in many newer Polaris secondary clutches. The helix rides against these rollers so they can wear out over time or even break if the machine is rode hard. Replace them before they damage the helix or clutch. Size is approximately 1" OD by .380" ID by .450" thick. Sold as a set of TWO. Exact replacement for Polaris part number 5439831. Fits the following Polaris models: 2014-16 ACE325 2017-19 ACE 500 2015-19 ACE 570 2016 ACE 900 2017-19 Ranger 500 2014-19 Ranger 570 (all models) 2014-18 Ranger 900 XP (all models) 2015-18 Ranger 1000 Diesel 2015-16 Ranger ETX 2015 RZR 900 (See note below) 2013-19 RZR 570 (See note below) (Depending upon the model the 570 and 900 RZR can use two different clutches. If your clutch uses a removable helix these are NOT the correct rollers. If your helix is part of the clutch sheave, these ARE the correct rollers)