This is a A-MB15 Bushing, Machine 1 3/8" X 2 1/8" 18 Ga. (Narrow Rim) PN: MB15Main Description As Following : A-MB15 Bushing, Machine 1 3/8" X 2 1/8" 18 Ga. (Narrow Rim) P.N: MB15 Gauge: 18Inside Diameter: 1 3/8"Outside Diameter: 2 1/8" Replaces: MB51 HARDWARE , Crossed From: BR22L , Found in Section & Models : Shop Supply > Machinery Bushings, (Miscellaneous) (UNDEFINED): SEVERAL Associated Items : New Also This is An Aftermarket Product And : Gauge: 18 Inside Diameter: 1 3/8" Outside Diameter: 2 1/8"