60,325 mm x 123,825 mm x 36,678 mm ISO 558/552A tapered roller bearings

tapered roller bearings offers a 60,325 mm x 123,825 mm x 36,678 mm ISO 558/552A tapered roller bearings NTN BEARING CORP.OF CANADA LTD. selection of Genuine tapered roller bearings at Wholesale Prices. 60,325 mm x 123,825 mm x 36,678 mm We Timken Brand are a 60,325 mm x 123,825 mm x 36,678 mm ISO 558/552A tapered roller bearings Certified Parts Retailer

What is 558/552A bearing cross reference？