This is a 124cc 54mm super high compp piston for horizontal engines such as monkeys. +R head has a compression ratio of around 13:1. Pin height 0.75 inch (19 mm) Pin diameter 0.51 inch (13 mm) Recess angle IN25 degree EX28 degree 54 mm stroke crank. (Except for kitacos) Daytona Dynahead is not suitable for use as it is low angles. Also, it cannot be used with regular heads or other genuine heads. Since it is cast not forged, please be careful when using it at high rotations. Pistons with low compression ratio cannot increase the compression ratio, so we have made it so that the compression ratio is as high as possible, and please adjust it according to your engine by processing the piston top.