Choose Options FMB Flat Mount Bearings PM MSRP: Now: $687.13 - $1,047.00 Was: These are instrument grade ball bearings. The first number is the bore size and the second number is the outside diameter. All units are in millimeters (mm). The letter N and P indicate quality class. N is normal and P is... Weight: 1.00 LBS MSRP: Now: $687.13 - $1,047.00 Was: Choose Options