105 mm x 190 mm x 50 mm NACHI 2221 self aligning ball bearings

LET 105 mm x 190 mm x 50 mm OUR 105 mm x 190 mm x 50 mm NACHI 2221 self aligning ball bearings EXPERTS 0.02 KGS Weight: GET YOU THE 14.8 Dynamic Load Rating (kN): PARTS NTN BEARING CORP.OF AMERICA YOU NEED.

What is 2221 bearing interchange？