It is a timer for mock exams, including the ability to practice solving the same problem repeatedly in a fixed time in preparation for the CSAT or to check the time in the middle of solving a mock exam subject. For example, if you leave 10 problems from 30 to 40 while solving the English mock test for 90 minutes, and you have 30 minutes left, if you set a check time of 30 minutes, a notification sound will sound when 30 minutes remain and the match mismatch problem will be set to 30 seconds. If you repeat 10 times of solving while solving, if you set 10 times in repetition and 30 seconds in seconds, a notification sound will sound every 30 seconds and the number of remaining times will be displayed.