Dodge Sleeve Coupling Hub, Finished Bore Flexible Type SC, Series: D-Flex, 09H Coupling, 1-11/16 in Bore Dia, 3-5/8 in Hub Dia, 1.97 in Hub Length, 3750 rpm Maximum, 3/8 x 2-3/4 in Screw, Steel Rounded EPDM and neoprene element edges for full tooth engagement, even load distribution, reduced stress build up, and longer lifeOutside diameter concentric to bore for ease in alignmentInterchangeable components makes installation quick and easyNo lubrication assures trouble-free operation