Exemption for sub-assemblies used in making auto-electrical parts extends to captive items when end-use conditions are met. Where finished auto-electrical components are cleared as original equipment parts for tractor manufacture at nil rate under notification No. 239/86-C.E., sub-assemblies produced and used within the same factory to make those finished components will also qualify for exemption if they fall under the chapters specified in the notification and the prescribed conditions, including Chapter X procedure and end-use verification, are satisfied.