Piston Kit - 77.00 mm - 13.5:1 CR - Yamaha Internal and external bracing, Dedicated embossed forgings for weight reduction, Specialized processes such as internal milling the internal struts, along with dedicated accumulator groove and forged side relief, Dome top features smooth radii, requires no deburring or preparation, Kit includes piston(s), wrist pin, circlip and rings unless otherwise noted, Made in the USA