23 INTERNAL COMBUSTION ENGINE AND ELECTRIC MOTOR DRIVEN PUMP UNITS, HAND OPERATED PUMPS, CENTRIFUGAL PUMPS, DIAPHRAGM PUMPS, EXCLUDING PUMPS FOR TRANSFER OF OIL HYDRAULIC FLUIDS, AND ACCESSORIES THEREFOR-NAMELY, TRANSMISSION DRIVE UNITS, WHEEL MOUNTED CARRIAGES, CARRYING HANDLES, IMPELLERS, BEARINGS, STRAINERS, LIQUID LEVEL CONTROLS, FLYWHEEL COUPLING ASSEMBLIES, FLYWHEEL ADAPTOR RINGS, SUMP COVERS, CURB RINGS, FLANGE ASSEMBLIES, BASE PLATES, AND FITTINGS; AND INTERNAL COMBUSTION ENGINE AND ELECTRIC MOTOR DRIVEN ROTARY AND STATIONARY DRUM MIXERS