A European binary with knock out (ebako) option is a European Binary option with an American knock out barrier.
For this option you set two barriers: one for the underlying European binary option and the knock out barrier. If the knock out barrier is hit at any time during the option's life, the underlying European binary option is immediately knocked out and there is no payout.
The fixed payout specified in the option is only made if, on the option's expiry date, both the following facts are true:
The knock out barrier has not been hit during the life of the option.
The underlying European binary is in the money.