Two layers make this the perfect form for those who need less weight due to lymphedema, arthritis, or other problems resulting in limited flexibility and muscle tone. The back layer contains a special lightweight silicone, easy on the back and shoulders, while the soft front layer creates a natural drape for an average to full shape. The Natura 3E'sasymmetric shape is ideal for women who need a little underarm extension, and who like the fuller shape.