the frequency of 37.5 kilohertz as the center frequency that we would be looking at. in the same way that we would be looking for, what is it, 121.5 for a beacon. but i'm just saying that the equipment can be set. it can be programmed higher or lower, depending upon what the application is. >> but no industry standard for -- >> not that i'm aware of. >> richard? >> absolutely fascinating. >> he's amazing. >> absolutely fascinating. really. so pull the strings together if you would. bearing in mind now what you've been saying and what you now know that they are engaged upon, how difficult is it? >> oh, it's very difficult. we're not talking about a swimming pool. we're talking about, from what i understand, about 15,000 feet