Features:Friability Detector BT-2 and BT-2AIt has two working modes of timing and countingWith repeat experiment functionWith pause functionFriability Detector BT-2A+Adjustable speed, adjustment range: 20-90 rpm can be set arbitrarily (default 25 rpm)With "chronograph" mode, the timing range is 0-9 hours, 59 minutes and 59 seconds, and the countdown can be selectedWith "counting" mode, 0 - 99999 times, and can choose to count down