Forged from high-silicon aluminum alloy for maximum strength and dependability. Innovative forging design and piston skirt provide maximum horsepower and torque. Dedicated forgings used for superior strength to weight ratio utilizing aerospace alloy. All Wiseco High-Performance Motorcycle Pistons come with rings and circlips. Fits:Polaris 250 TRAILBOSS/TRAILBLAZER Thru 2005.