The basic Grid-Lign coupling consists of two steel shaft hubs, a high strength spring steel tapered grid element, two seals and a cover assembly. Misalignment and end float are accommodated by the sliding action of the grid in the lubricated hub grooves. Dodge Grid Coupling Hub, Type T10/T20, 1080T Coupling, 2-7/16 in Bore Dia, 4.13 in Hub Dia, 5/8 x 5/16 in Keyway, 3600 rpm Maximum, 3-1/2 in Length Through Bore, Steel