3-Piece L090 Series coupling set includes two coupling Hubs & NBR rubber insert. 1/2" bore with 1/8" keyway and set screw on one coupling Hub. 1-1/8" bore with 1/4" keyway and set screw on second coupling Hub. Compatible with Lovejoy, Martin, Browning, TB Woods, and other L-jaw couplers. Include - 1/2" Hub + 1-1/8" Hub + L090 Spider General purpose straight jaw coupling hubs attach to motor and equipment shafts using a set screw or keyway. Two couplings of the same size are locked together with a compatible straight jaw spider. These hubs are interchangeable with other brands according to the coupling size identifier.