The ball bearing flange unit has capacity for higher speeds and allows for minor misalignment. It generates little friction and provides shaft support for high precision applications. The 4-bolt, square flanged unit is the standard in the industry. Martin Ball Bearing Flange Unit, Round Bore, Series: TEB, 1 in Bore, 2-3/4 in Bolt Center-to-Center Length, 3/8 in Diameter Bolt Circle, 4-Bolt Flange Mounting, 3-3/4 in Overall Length/Diameter, 1-3/8 in Overall Depth, 3-3/4 in Overall Height, Cast Steel Bearing, Protective Coated