what and how rollover level works?

The rollover level is the price level where the ZigZag will change its direction if it reaches that level.

Hello Petr Nosek again.

can you not please add the inputs of zigzag ie 12, 5 & 3?

and if you have the option of switching or reversing the fibo projection 0 & 100 in opposite direction as well?

I'm sorry, but I guess I misunderstood what you wanted me to do. You can enter whatever inputs you want as long as they make logical sense. Logically, the parameter that enforces something must be higher than the parameter that allows/disallows something. In other words, the input parameter "ATR multiplier that forces a trend change" must be higher than the input parameter "ATR multiplier that doesn't allow a trend change". So you can use inputs 12; 3; 5 , but you can't (for the logical reason) use inputs 12; 5; 3.