Namura, NA-50008K, Top End Repair Kit Polaris Scrambler & Predator 50 Standard Bore 40mm Namura piston kits with gaskets include everything you need to restore the top end of your bike to factory fresh specs The kits are complete with pistons, rings, and all gaskets and O-rings needed to complete a top end rebuild Piston kits are precision machined to Japanese OEM specifications, using low-expansion, low-friction piston alloy resulting in an extend life span of the piston Namura gaskets are made to exact OEM specs but with better materials to last longer and keep your bike running stronger