They have an inferior product which is poorly designed, implemented and warranted. Electronically they function, but mechanically they invariably fail after minimal use. I have had four of their original headsets and three of their redesigned headsets, all of which broke on one side making them useless. My last one, which I received in October, broke this week. I promptly called them; they asked for $50 to replace it, not honoring their guarantee and implied warranty to supply a quality product. I am a consulting engineer and can vouch for the fact that it is poorly designed for it's intended use. I do not recommend that anyone purchase their products and thereby encourage them to shaft the innocent and naive public. Here is a great eample of caveat emptor!