At what ET do you need a cage?

the rule may have

i know it was a 11.99 and under u need a 5 bar one bar but every 1 just does the 6 bar cage and its good to a 9.99 and faster than that u need a 10 point and that was good to a 7.50 but the rules changed and a 10 point is only good to a 8.50 ms and a 8.30 cm. i had heard the 11.49 is only good for cars that can run that fast stock
 
i know it was a 11.99 and under u need a 5 bar one bar but every 1 just does the 6 bar cage and its good to a 9.99 and faster than that u need a 10 point and that was good to a 7.50 but the rules changed and a 10 point is only good to a 8.50 ms and a 8.30 cm. i had heard the 11.49 is only good for cars that can run that fast stock

What?????