Large and color screen
Forced Vital Capacity (FVC).
Forced expiratory Volume in one second (FEV1).
The ratio of FEV1 and FVC (FEV1/FVC).
Peak expiratory flow (PEF).
Information prompts when volume or flow goes beyond the limits.
Automatic power off when there is no operation in two minutes.
Rechargeable lithium battery and with charging tips.
Battery power display.
USB Socket for PC Software
Bluetooth module built-in
