Dangerous Tyre

Here's a front tyre with a crack on the inside wall.
There was no way of the owner knowing as it could not be seen from outside & there was no vibration when driving. The owner was quite shocked when he realised what the consequences could have been if this tyre blew out on his high performance car.
Tyres are mostly overlooked, but are very important, being the only thing between the car & the road.
N. W.