Dodge Sleeve Coupling Flange, Finished Bore Flexible Type S, Series: D-Flex, 012 Coupling, 2-1/2 in Bore Dia, 5-3/4 in Hub Dia, 1-1/4 in Hub Length, 5/8 x 5/16 in Keyway, 2800 rpm Maximum, 4 in Length Through Bore, Cast Iron 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