Small, portable, quiet; but pricey. Failed after two plus weeks, requested replacement. Shall wait and see if the first one’s failure was a coincidence or it’s a flaw in the nebulizer.Portable and convenient nebulizer machine for emergency use. Does come with 2 sizes for the mask and a nozzle, but it is not the standard looking one as with the other machines, so there is a small learning curve to work with the one provided.I like this portable nebulizer. It was packaged well it works makes zero noise and it's travel ready with the carrying case . I have to be honest though it is a little pricey so I took one star off . It does what it says and that makes me happy . ?Review of: Yirdoc NEB-002, Intelligent Mesh NebulizerThis product comes in a small portable bag, which is approx 6" x 5" x 3". Inside is the nebulizer, an adult mask, a child size mask and a mouthpiece along with a charging cable and instructions.The unit has an 1800 mAh, lithium-battery that is charged on the bottom via a USB Micro port. (they provide the cord, you provide the charger). You can get up to 4 hours of use on a full charge.I was really surprised how small this device is and is easy it is to hold in your hand. It is also extremely quiet.There are two indicator lights on the front. One is below the button and will glow orange when you are charging the battery. The other is above the button and has two modes. When you press the button, it activates the device and the light will glow green. (If you see the light flashing green, that is the low liquid indicator and the unit will shut off when it runs out.) If you hold the button for several seconds, the light will flash from green to blue, indicating you have put it in 'cleaning mode'. (It will run for a couple of minutes and then shuts off.) There is a mechanical release button on the back of the unit. When you push it, you can slide the entire clear plastic cup forward and off for cleaning.I have been using a '0.9% Saline Solution for Inhalation' (from Amazon) in individual 5 ml doses, and when my chest feels congested, and I start coughing, using this nebulizer makes me feel better. Also, it is nice to know I can take it with me just about anywhere.Note – when I first received this Nebulizer and I had a technical problem with it. I contacted the seller (WUUAIR Store) and they resolved the issue in a very timely manner. That's good customer service and support.Very pleased and would recommendThis review is for Portable Handheld Machine with Upgraded Design and Convenient for use.The size is convenient. You can take it anywhere which is so useful. It works well and it's very well-made.