One-piece sleeve coupling inserts join two compatible coupling flanges to complete a sleeve coupling system. JE, JN, and H sleeve inserts are constructed of one solid piece, while the JES and JNS inserts are split for easier installation where the coupled shafts are mounted close together. No Lubrication, Quick, Easy Installation, No Maintenance, Clean Quiet Performance. 4 Way Flexing Quick, Easy Installation Clean, Quiet Performance Agitators, Blowers, Pumps, Machinery, Mixers, Packaging machinery, Gearboxes, Machine tools