Athena (S4C05400016A) 53.94mm Cast-Lite Piston Kit Fits: Yamaha YZ 125 LC Factory 1997-2004; YZ 125 LC Factory 2005-2014 Specifications: Standard Bore-53.94mm (A) Cast Piston Kit Athena developed their Cast-Lite pistons specifically for use in the off-road/ATV market and manufactured them using a revolutionary computerized technology originating from GP and F1 racing Athena Cast-Lite pistons offer the best solution in terms of performance and reliability thanks to redesigned squish areas, modified compression characteristics and advanced surface treatments Piston is sold complete with rings, wrist pins and circlips