This is a NEW Set of BMW M10 JE 2618 Forged pistons:
Complete set of 4 with Pistons, Pins, Locs and JE ProSeal Rings
90mm Bore Diameter
10:1 Compression Ratio
E12 Head with Valve pockets for  47mm / 39mm Valves and 304 Cam
For use with 144mm Long Rods Only. NOT for use with Stock Rod Length. 

Long 144mm Rods available separately. ( $599 with ARP2000 Bolts. )