Providing a reliable solution for uniform to heavy shock loads, this durable jaw coupling hub is directly interchangeable with industry standard couplings. It's designed for extreme conditions, and is ideal for use with variable-speed and variable-torque applications. No lubrication or maintenance is required. Note: A complete assembly requires two hubs and one jaw coupling spider, available separately. This listing is for each. Technical Specification Item - Jaw Coupling Hubs Jaw Coupling Hub Size - Jaw Couplings L150 Bore Dia. 1-1/2 Keyway Size Type 3/8 x 3/16 Material - Hubs Sintered Iron Outside Dia. 3.75 Assembled Coupling Length 4.50 Overall Length 4.50