 That little blood oxygen meter thing, likewise. That's the real deal. And the one that's tricky, though, is doing the one at night. How much time do we have? We have five minutes. Good. Let's talk about this one. Four and a half. One of the things that's super important for people to be healthy is you have to get oxygen at night when you sleep. And lots of us don't breathe correctly at night. And we get sleep apnea. There's other things that go wrong, but just pick the most common one. Sleep apnea. Sleep apnea.