 You'll see the wear on it. If that electrode on there has got a groove worn into it, it's time to change it. Or if you've got a lot of heavy buildup on them and they're fouling because of very short trips, like maybe you start it and you drive it a couple blocks and park it or start to move around the garage, they might be starting to foul where it's time to change it. But it's an 02. I mean, we're talking 20 years old, 23 years old.