R450-7A excavator spare parts slewing bearing slewing circle with P/N:81NB-01022BG

Small Slewing Ring offers 0.108 Misalignment factor k1 a 249 mm Da max. R450-7A excavator spare parts slewing bearing slewing circle with P/N:81NB-01022BG selection of TFI Bearing Co.,Ltd Genuine Small Slewing Ring at Wholesale Prices. We are a R450-7A excavator spare parts slewing bearing slewing circle with P/N:81NB-01022BG Certified Parts Retailer

What is R450-7A bearing interchange？