26 SPARK PLUG TESTERS; CONDENSER TESTERS; MOTOR AND IGNITION TESTERS; COMBINATION COIL AND CONDENSER TESTERS; IGNITION COIL TESTERS; ARMATURE TESTERS; IGNITION COIL PREHEATERS USED IN CONNECTION WITH IGNITION COIL TESTERS; SUPPRESSOR TESTERS; GENERATOR, STARTER, CUT-OUT, AND VOLTAGE REGULATOR TEST UNITS; TEST STANDS FOR TESTING AUTOMOBILE ENGINES; VACUUM AND COMPRESSION GAUGES FOR USE IN ENGINE TESTING