172cc malossi piston

What is the difference between these pistons: Art.-no. M348512 and Art.-no. M348512A0 ?  Are piston rings included too or it is only piston?



look on your old piston head, there you see a letter of the oversize that these pistons have. Look if it is a A,B,C,or D


than order your piston in your size/letter