30 mm x 72 mm x 19 mm KOYO NUP306 cylindrical roller bearings

KOYO Bearing offers a 30 mm x 72 mm x 19 mm KOYO NUP306 cylindrical roller bearings selection of Genuine 30 mm x 72 mm x 19 mm KOYO Bearing at Wholesale Prices. Open Type Seals or Shields: We are BEARING Driveshaft USA CORP. a 30 mm x 72 mm x 19 mm KOYO NUP306 cylindrical roller bearings Certified Parts Retailer

What is NUP306 bearing cross reference？