Replacement piston for 39mm MBK Polini av10 kits. Produced specially for us by an Italian manufacturer with 50 years experience. Some slight differences exist between these and the ASSO cast one that probably came with your Polini- notice the lack of scallops on the side. Single ring! Choose your size!
A= 38.95
B= 38.96
C= 38.97
D= 38.98