Leica Bakelite Lens Cases The Complete Set From Left (135mm Hektor, 90mm Elmar, 50mm Elmar or Summitar, 35mm Summaron) These Bakelite cases are rather difficult to find.  They are and were, the ultimate in protection for your Leica screwmount lenses.  They make your lenses easy to carry along without having to worry about damaging your lenses in adverse conditions.  The top unscrews and the lens slips in.  The lens is held snugly in place by plastic ribbing inside the tube.  The Bakelite used to manufacture these cases is very very durable.