1. LCD screen, can display the remaining battery, speeds, pressure value, using time.
2.Four speeds, different speed means different presure value,the presure value will growing up
with the speeds.
3. Automatic start and stop. The maximum negative pressure value of the first speed is -
125mbar, when the presure value growing up to -125mbar, the machine will down to -50mabr,
then it will growing up again, until it up to -125mbar. It will automatically cycle between 50 and
3.it was usb charing one.