All piston skirts are coated with a hi-tech Molybdenum Disulphite coating for faster break-in time and increased piston life Cast Replica piston kits are gravity cast aluminum alloy (not forged) with 18% silicone content, which produces an extremely light but very strong piston Forged Replica pistons are forged from 2618 aluminum for superior strength and durability Forged High Compression pistons improve power and torque across entire rpm range Forged Big Bore pistons increase engine’s displacement, torque, and peak horsepower Forged Replica pistons are forged OE replacements All pistons are heat treated with a T-5 hardening and tempering cycle Replica pistons and all rings are OEM replacements Kits include piston, rings, wrist pin and circlips **************************************************************************************************************************************************************************** PLEASE VERIFY FITMENT BEFORE PURCHASE: 2016-2022 KTM 450 SXF 2016-2022 HUSQVARNA FC450 2021-2023 GAS GAS MC450F