6,35 mm x 12,7 mm x 4,762 mm 6,35 mm x 12,7 mm x 4,762 mm ISB R188 ISB Bearing

ISB Bearing 1.5000 in outer ring width: offers a 6,35 mm x 12,7 mm x 4,762 mm 6,35 mm x 12,7 mm x 4,762 mm ISB R188 ISB Bearing selection of 6,35 mm x 12,7 mm x 4,762 mm Genuine ISB Bearing at Wholesale Prices. We are a 6,35 mm x 12,7 mm x 4,762 mm 6,35 mm x 12,7 mm x 4,762 mm ISB R188 ISB Bearing Certified UBC Mechanical Electronic Instrument Co., Ltd. Parts Retailer

What is R188 bearing cross reference？