The O2 Flow Electric Face Mask cuts back on waste from disposable masks while purifying the air you breathe in and reducing moisture build-up inside. Along with the soft silicone construction, adjustable ear loops, and included velcro band, this mask will stay comfortable even when worn for longer periods of time.The O2 Flow includes a replaceable four-stage HEPA filter with activated carbon, a sterilization membrane, and medical non-woven fabric construction. Perfect for all kinds of particulate matter, such as viruses, bacteria, exhaust gas, formaldehyde, pollen, dust, and allergens, it can filter particles above 0.3 microns. When used properly in ideal conditions, the purification efficiency is as high as 98.8%. The two-speed fan allows you to breathe normally, even when exercising. Combining aerodynamic principle and the design of a 3-dimensional purification air duct, the diffused air intake has a sufficient air intake volume to provide up to six times the fresh air required for normal breathing every hour. Both the mask and the adjustable ear loops can be sterilized for reuse.The active exhaust valve is based on aerodynamic principles. When you exhale, air pressure is generated internally. When the pressure inside the mask is greater than the external atmospheric pressure, the exhaust valve is automatically opened. Because the exhaled air is discharged from the lower exhaust valve, the mask can fit closer to the face without causing condensation build up. The continuous air flow also helps prevent bacteria from breeding inside your mask. The silicone ear band can be adjusted and combined with the velcro protection belt to fit the mask close to your face, ensuring a snug fit that won’t fall off. The velcro and ear bands can also be removed at any time, and you can choose how you want to wear them.Note: Before purchasing, please check with local guidelines and recommendations to see if this product is suitable for your intended use.