4WDKING Rechargeable HEPA Air Purifier - Portable Air Cleaner for Home, Office, Travel & Outdoor Activities | Eliminates Dust, Pollen & Odors | Aluminum Housing | Ideal for Sleeping, Sports & Housework

Just received this and charged it, and letting it blow out for an hour to remove plastic vapors from the hose like the instructions say. (It does smell very plastic/chemical at first.) The airflow rate feels good and I don't feel any leaks from the case or hose. It's not loud at all, a very slight motor sound with a little more air sound. I can tell it's on if I listen for it, but it's not intrusive. Case is actual metal, seems strong, and weighs much less than I was expecting it to from the appearance, slightly lighter than my TV remote with batteries in it. It doesn't come with a charger but the port is micro-USB, so compatible chargers should be plentiful. The two screws holding the front plate on are very tight though, made removing the cover to take off the plastic shipping barrier from the battery difficult. It's not something I'll need to open often given the estimated filter life, and they may be looser now, but I'm concerned they may not last. I don't think the threads are stripping but the Phillips heads are a bit worn after just one time. I may replace them with flathead slots to make opening it easier. The on button is a bit sensitive and nearly flush with the surface, just something to remember when grabbing the unit to check that you didn't turn it on or off or change the blower speed by accident. If they make a version 2, a raised ridge around the button to prevent accidental presses would be a suggestion. Will update after getting a chance to actually use it, but so far so good.The masks it came with seem to be good quality KN-95. Since it's a powered air feed system blowing clean air inside rather than requiring you to suck air in through the mask material by lung power, they should clog less often than the same masks used as an unpowered KN-95. Fit will be important to protect others though, if they don't sit well on your face there could be some leakage of your breath. Not much else to say about them. The hoses are soft but seem pretty resistant to kinking. They are easy to get on and off the connectors. They're an unusual size, the seller answered a question with the exact dimensions previously. I was hoping they'd be the same diameter as a CPAP hose but they are not, they're smaller.I don't know what their lifespan is yet but replacement hoses are available from the seller and not expensive. I would like to get some more replacement connectors too but haven't found them yet. It's not clear from the item page, but one of the connectors is for joining the long and short hose into a longer single hose, and the other is for attaching the hose to the mask. The mask adapter seems to rely on the hole in the mask being slightly smaller than the connector so it stays tight. It won't and can't fall off, it just could leave a gap and leak if you're not careful about cutting. One mask is pre-cut and the others are not. A little sticker is included to trace the hole size around.Besides the screws, the main issue so far is the instruction manual. The English isn't bad, and it gives some good tips I wouldn't have thought of (like keep it in a pocket if you use it in really cold weather or it will feed you unpleasantly cold air, and tie a cloth over it to extend the HEPA filter life in dirty environments), but it doesn't explain a lot of common things, like how long to charge, or what the 3 LEDs on top mean when they glow or blink in certain colors. All three blink red when charging, and glow solid at what I'm guessing to be full charge. Charging didn't take long but I don't know how empty it was fresh out of the box. They don't seem to count down to full charge by blinking or glowing separately, they just all blink and then all glow solid. When running two of them are green, and one is orange (seems to be a mix of red and green). There's no change in them at different fan speeds. Maybe they're indicating the remaining battery level but I haven't gotten it down past the first third yet? Anyway, will update later, but found this interesting enough to write a review of what I've seen of it so far.TPer instructions, the first thing one has to do is remove the battery insulation film, which involves removing the cover. Unfortunately the screws are very tight and difficult to remove initially, so much so that one screw stripped and cannot be removed. Per instructions you need to connect the mask and tube and blow off the rubber smell for one hour before use, so I did. the air flow thru the mask was very comfortable. Did not do for an hour as there is a funny smell coming from the unit without the hose attached, which is probably the battery film I cannot remove and didn't want to burn the unit up. If I can figure out how to remove and replace the stripped screw, I think this will be a good thing to use.UPDATE: The company within one day of contacting them offered a refund or replacement, and is informing their engineers of the issue with the screws. Since there is no battery insulation to be removed, I tried out the mask. The mask fits comfortably with no gaps. The air is comfortably cool, and with 3 settings can be adjusted for flow. You definitely won't need the highest setting unless you are exercising. The funny smell wore off after about 45 minutes of use, and your voice is not garbled. The unit is very quiet. I tried wearing it on the back of my head, and it fit & was comfortable, but you have to be careful about the Velcro or it can irritate your skin. If you have a larger head, this would not be comfortable with the enclosed strap. I next tried it on my arm. It is best to wear over clothing ( or lab coat). Easiest to connect the strap and then slide it into place.i didn't need to use the hose extension, but I am only 5'2". If I had to move more I would use both hoses connected together. If wearing around your waist you will need to use your own belt and definitely both hoses. I would recommend this product to anyone who has to wear a mask for an extended period of time.My life depends on the clean air I breathe!!! I saw this and had to buy one. It is my opinion that this tiny yet simple device could possibly mitigate your chances of picking up the dreaded COVID 19 Virus. YES! We must all be diligent, wash our hands, not touch our face and adhere to social distancing practices but an extra precaution would not hurt. How about breathing air that is run through a HEPA filter?This is such a simple concept. A box, a filter, a fan, a battery and switch, and a supply tube. So simple and self-contained and it could possibly be a live saver. I like it because I am not constantly re-breathing what is inside my mask. This device introduces FRESH FILTERED AIR directly into the mask. One thing I like is the fact my glasses do not get steamed up. As I mentioned before my masks don't start smelling bad so soon because it is not so damp and the other good point is you are not breathing back in the carbon monoxide you are exhaling.Please note!!! This mask may be an added step of protection for you but it could be harmful to others. Due to the positive airflow inside the mask incoming air forces out some of the sir you exhale. Also, have you ever sneezed or coughed inside your mask? This can affect other people around you. This mask is really only helpful to you.Note: My HEPA cartridge had a slight chemical odor when I first turned it on. I ran it a few cycles before wearing it.