 Brain waves. It is wild. And you get to see it firsthand. There's one of our technicians, Jen, who's an expert at this. She's a ninja. She said she could see it and she's tracking it as you're going through your training. And so, like I said, you just watch a movie and your brain does it all on its own. And so your each training is about 20, 30 minutes. I think the map itself is anywhere from 30 to 60 minutes because we got to get a really good first establish that baseline.