By selecting this option you will have a guarantee that the key will be done within the given time limit which is set differently for each dungeon. If you haven't selected this option we will still do our best to beat the time, however, there will be no guarantee. In case you purchased this option and we fail do beat the timer, which is an extremely unlikely event, we will run the key again as many times as it's required until we beat it. No extra cost is applied for additional dungeons in this case.