The five stars are purely for the quality and workmanship. This is indeed pure copper and it is crafted perfectly without any flaws and is aesthetic. Sometimes handcrafted items are poorly done with shoddy craftsmanship, but this one is very good. They sent a copper tongue cleaner and a small packet of "Pitambari" powder with the bottle.The stated capacity is 1050 ml, but the one I received is 1075 ml when filled fully to the brim, and when I screw in the lid fully it displaces around 40 ml and hence the actual usable capacity is 1035 ml, which is pretty good as most copper bottles being sold are below 1000 ml. I am not sure if this is the case with all pieces as it is a handcrafted item and it may vary slightly with each piece as each one will be unique.Now, to the practical aspects...I have seen many online reviews of copper bottles negatively stating how it lost its shine and turned to a different color and hence it is not pure copper. Though the bottle is bright, shiny, and attractive when it is new, you should understand that it will not stay the same when you start to use it as copper tends to oxidize, although it happens slowly with electrified copper. This is the case with all pure copper items. So with use this will lose the shine and also it picks up stains when touched with wet or sweaty hands. It takes regular washing with lemon or "Pitambari" powder to remove the stains and to keep it looking like new. Over time, it loses the shine and takes on a dull rustic copper brown color which is perfectly normal.Regarding it being leak-proof, I think it is not possible to make a metal water bottle with a metal lid totally leak-proof. To achieve this, you need to integrate other synthetics in the lid mechanism like they do with stainless steel thermos, but this defeats the whole purpose of avoiding synthetics. That said, the lid of this bottle is quite well-made and screws in perfectly, but it is not totally leak-proof even with the provided silicone band. Water drips slowly drop by drop if you turn it upside down or keep it horizontal. So you have to be careful to always keep it close to vertical in your bag while traveling. Screwing the lid in very tight might help to some extent, but not completely, and I would not advise this as you would end up damaging the threads over time.Apart from these two unavoidable issues, this is one of the best copper bottles you will find.Update: It has been more than 3 months since i have been using this now and I am just loving it! I drink from it the whole day and I even carry it to work. The main reason for this update is I wanted to show how it looks after three months of usage and just washing with plain water. Yes, thats right, I just swish it with plain water once a week or so; no soap, no agents, no Pitambari and sometimes I just wipe it with wet cloth on the outside and a few other times I just don't bother at all... because I just don't have the time to do all this cleaning stuff! In spite of it, the bottle does not look that bad as it is being made out by some reviewers (see last pic; the difference in color in the center is because that is where I grip it most and hence more oxidization there). So basically I think it is quite maintenance-free provided you are willing to accept the way it looks. Now you must be wondering what about hygiene? Well, copper is antibacterial so its fine as long as you use it normally with clean hands and don't get it real dirty. Regarding the squeaking sound while screwing the lid some people are complaining of, it is unavoidable when both the lid and the mouth of the bottle are made of metal, just screw it very lightly with a feather touch and there will be minimal to no squeaking.