Some bearing manufacturers (typically far eastern) produce bearings in non standard sizes but use standard seals to keep the costs down, this results in a missmatch between what the seal says on it and what the bearing measures up at. If in any doubt, always go with the measurements rather than any seal markings.
All bearings are quoted in the size d x D x B, where d is the inner diameter, D is the outer Diameter and B is the thickness. And, inside diameter (ID), outside diameter (OD) and Width(W) are used for clarity.