11 Heating Apparatus-Namely, Electrical or Fossil Fuel Fired Industrial Furnaces, Driers, Kilns, Lehrs, and Industrial Ovens of the Shuttle, Box, Envelope, Pit, Tube, Car, Elevator, Tunnel, Pusher Slab, Belt, Crucible Tilt and Bell Types; Chemical Strengthening Units of the Electrically Heated Batch and Bath Furnace Type; Metallic and Non-Metallic Electrical Heating Elements; Furnace and Kiln Maintenance and Repair Parts