 So can I have a go? Yes, you can. We have this device here, which just looks like a little tennis headband. Oh, it does. Yes, it does look just like a sort of headband for tennis. It's white at the front and grey at the back. Do I put it on my head? You put it on your head, yeah. OK. What happens next? So we can start one of these apps. So this just comes with the brain device. So you've got a tablet here with an app on it. Yeah. Oh, look, it says it's calibrating. There's a picture of the brain.