66/80cc piston 47mm diameter, higher hole 30mm or 1&1/16" ( see picture measurement) . item include : 1 higher hole piston and 2 rings. For 66/80cc 2-stroke gas motor bike engine which has long connecting rod bottom end. Please check the measurement of the piston size before buy. It is very normal has some scratchs on the piston ( not the damage). The important is the rings not broken.