A curable composition and method for producing a tear resistant, yet soft and deformable in-the-ear product yielding the user greater comfort and durability. An embodiment of the present invention relates to a method of treating a gas containing a fluorine-containing compound, comprising contacting the gas with a treatment agent comprising a mixture of aluminum hydroxide and calcium hydroxide. The tank body includes an upper and a lower flat surfaces facing the lower flat surface of the upper exterior member and the upper flat surface of the lower exterior member.