144 replacement piston size?

[adub24]

I have the athena 144 for a yz 125. I am trying to order the piston kit and it shows 2 sizes 57.94 or 57.95 . I spoke with an online tech they told me either would work with no changing of the cylinder they are both bolt on and go . I have no cylinder damage I just need a new top end which one should I get?

 

[Rich Rohrich]

Measure the bore, then you'll know without guessing.