I was pleasantly surprised at the quality of this - very good fit and finish and I don’t think if you bought this in a dive shop it would look any better. The shoulder holder works well. Those are the pluses. There are some minor minuses which I will list here:The gauge is a little hard to read the numbers, but once you figure out what numbers go with the color code, you’re fine.The mouth low pressure valve is a little sticky - in other words, as you breath in, it really takes a good bit of negative lung pressure to get it to activate fully. It wasn’t too bad - I like it a little bit that way so you don’t use so much air. Also, the front unscrews easily and comes apart nicely. There is a tiny nut on the actual valve and it looks like this may be an adjustment for this. Haven’t gotten around to looking for my tiny wrenches yet.The directions are OK, but not very detailed - for instance there is nothing about adjusting the second stage valve and the English is OK, but not great.The little cap that covers the fill nipple is not a tight enough fit. This lets water get into the fill nipple which if you’re not careful, will end up in the tank when you next fill it.Worst off, the low pressure hose smelled terribly of industrial manufacturing. Not breathing grade. I soaked and rinsed off the secondary valve and hose, and noticed a slight oily residue on top of the water. Then I assembled it and pumped up the tank to about 2000 psi to try it out. After 5 minutes using it in the pool, my lungs started to burn. I stopped, and let the air out. I rinsed out the hose several more times, noticing there was still a slight oily residue on the water. I also washed out the interior of the tank this time. I’m afraid they used an industrial hose instead of one specifically for breathing. However, it is also possible my pump contributed to this. I do have an oil-free pump, but I will now get the tank filled with scuba air and see if I notice a difference. If I do, I will update here appropriately. If my lungs continue to burn and I can determine it’s because of the hose, this will end up a one-star.Really enjoy scuba diving so next best thing is having this little tank to be under water for 20 minutes or so. Easy to use and carry.Best Quality, Best Packaging, Smooth Operation.Outperforms Dive Portable lungs that sells for $295 or more. Plus will be forced to pay an additional 40 dollars on flat rate shipping. If you just buy the cross body bag by itsel. It will cost you $19.95. But the shipping rate again, would be $40. More than the item itself. Isnt that ridiculous?. Smaco at least from a Solid company that also have other accessories. If you want prove of this item performance and compare to Dive Portable lungs. Check on my videos on Youtube. Diving with these tanks. Just Type Smaco S400. You will see my Yellow regulator in a swimming pool. Thats the Dumbnail. My channel profile picture is a Baseball player. Check on the video. Hit the like and share its link. The S400 is really a solid unit so far, no issues. If you would like to have 1. Contact me though my video comment section, on youtube. And i share with you,, the supplies you need for your S400 tank. It's a shame, the review from the Dive Portable lungs brand owner. Over this product, the Smaco S400. He have not even used this profuct to give an honest Review. And he is bashing on it, because he is the Owner of a tank and smaco is competition for him. Makes no sense to say. That the Smaco S400 is a waste of money, over its design. Absolutely Ridiculous. And i personally love the S400 Workmanship, and i take my hat down to Smaco. Please whoever have the power to remove reviews on amazon. Please Take down that review from Cameron. Is not honest and has no logic. He is just an opposing competitor. In the Portable scuba industry. He is just trying for people to not purchase these tanks, from any sellers. As flygoo. Someone check on him on Facebook, Instagram. Dive Portable Lungs Owner Cameron Barbeau. He ships his tanks and Pump with no protection in a prepaid USPS Box. And the tank's hardware, such as the 2nd stage, or tank connections may leak air, within its use. The gauges get full of water, and its condensarion turns the gauge Blurry. He increased the price from his little tanks starter kit, with no workmanship upgrade. To $895.95, from $695.95. Whenever he releases the larger tank to retail. For sure will go behond $1,000 dollars. And the Smaco S400 will still lead in design and performance. His larger tank will use the same cheap Aluminum connections.I'm a solo diver and bail out is extremely important, this is a great light weight bail out tank for light weight shallow dives (50ft max by professional divers, 20 ft just certified divers). i decided to make a bracket to attach it to my main tank and love the way it looks. @ 50ft with very controlled breathing and a short deco stop this will barely get you through it. @30ft a full deco stop is possible with the same controlled breathing. After a few dives i swapped the first stage with the s400pro first stage and swapped out the second stage with a less restricted one.If your brand new to this obviously get your diver cert first but i can't stop you so all i can say is get whatever training you can get, do not go more than 10-15ft and vary important BREATH OUT WHILE HEADED TO THE SURFACE.Great customer service replaced a faulty compressor quickly with no hassle.I highly recommend.The product I ordered arrived earlier than expected.Everything works and I use it whenever I dive... Just about daily.I am very happy with this tank. It is well made and durable. The regulator works really well. I can breath as easy out of it as my normal regulator. It comes with the backpack style case to use underwater. If you use the case to hold the bottle on your back you can not see the gauge, so be aware of that. Also you will need a way to fill this bottle. I have the attachment that allows me to fill it off a full size tank. It is best to fill it off a full tank as it will only transfer as much pressure as the full tank has. You can also purchase a high pressure hand or electric pump. This tank is easy to assemble and disassemble if you want to be able to travel with it. It also comes with an extra set of o-rings, so that is nice.I liked it very much I use it to check on the Neath my boat after I hit a rock