1.Lower voltage 2.Easy to use with one-key operation 3.High accuracy and repetition 4.Automatic Power-Off without signal for 8 seconds 5.SpO2 and pulse monitoring,histogram of pulse display 6.It is light with gross weight of 60g,small in size,and easy to carry 7.Two AAA batteries are required for operation with low power consumption,and the continuous working time is 100 hours. 8.Six colors selection