There is one kind of tungsten silicone-based shielding product, that made with tungsten, iron, bismuth or mixtures of these metals. The advantages of tungsten silicone-based shielding are base on the good performance of tungsten, iron, and bismuth. Tungsten silicone-based material offers the ability to put the shielding as close as possible to the source.http://www.td-tungstenshielding.com/tungsten/