Nebulizer Esperanza MIST generates the aerosol by the new mesh technology. Thanks to that, the soundless operation of the device enables your discrete use even with a sleeping baby aside. Thanks to the true portable size, the device can fit in any handbag or briefcase. Running up to 4 hours on just two batteries, your medicine is always within reach wherever you go, whatever you do. Power supply: 2 x AA Alkaline battery 1.5 V ( not included ) / USB cable Power Consumption: approx. 1.5 W Ultrasonic Frequency:  103 KHZ~123 KHZ Standby Current Consumption: < 0.1 mA Working Current Consumption: < 500 mA Medicine Capacity: 6 ml Average Nebulization Rate:  ≥ 0.2ml/min Particle Size (MMAD):  3 to 5 μm Aerosol Output Rate: 0.087 ml/min Sound level: ≤ 21 dB Automatic Off: no medicine / after continuous working for 20 minutes Operating Temperature Range: 10°C ~ 40°C (50°F ~ 104°F) Operating Humidity Range: 10% ~ 95% RH Storage Temperature Range: -20°C ~ 50°C (-4°F ~ 122°F) Standard Package: main unit, nebulization unit, adult mask, child mask, mouthpiece, pouch, USB cable, rubber protective cap Product size: 6.0 x  5.5 x 13.0 [cm]