Spare inner rings (axles) for RWC Needle Bearing Kits:

NBKRWC2540
NBKRWC30
NBKRWC3383
NBKRWC3556
NBKRWC38
NBKRWC3998
NBKRWC4115
NBKRWC4374

The tolerance range refers to the relative Outside Diameter of the inner rings, which vary slightly to accomodate variations in shock eyelet bore Inside Diameters.