United Scientific® Unistore™ - 12 Pack 1 Oz (30ml) Laboratory Grade Polypropylene Wide Mouth Reagent Bottles with Lids - Sample Containers for Travel, Cosmetics, Essential Oils & DIY Projects

Note: this bottle is made of food-grade plastic. The product info on Amazon doesn't mention it, but you can find a statement saying so on the company's website. I use it for mixing and storing meal replacement drinks, and it seems to work well so far.Comparing this (4L polypropylene bottle) to a Nalgene brand 2L high-density polyethylene bottle I own, it find the material to be sturdier / more rigid, which could be a good or a bad thing. It's not as smoothly machined as the Nalgene bottle - you can easily see and even feel the seams in the plastic where edges of plastic sheets were joined together.The Nalgene bottle's cap is a single piece of plastic that screws on with a snug fit, whereas this bottle's cap is not as perfectly fitted and comes with a rubber ring inside to ensure it seals properly. The rubber ring needs to be removed and washed separately, which is an extra hassle compared to the Nalgene bottle. Perhaps it's inevitable due to the materials, though; it may be that this bottle's rigidity makes it harder to get a good seal without a rubber ring, whereas the Nalgene bottle is more pliable, allowing its cap to "bite into" the lip a bit.The rigidity also means that if the pressure in the bottle changes (e.g. if you put in a hot liquid, close it, and let it cool), it can be difficult to wrestle the cap open again, so watch out for that.Other reviewers have mentioned this, but the bottle doesn't come with any "United Scientific" branding on it. Instead, it has "PolyLab" and "4000mL" embossed on the bottom. I don't think that means it's counterfeit - if you look up import records, PolyLab appears to be an Indian company that serves as a supplier / manufacturer for United Scientific, so I wouldn't be too worried.Other than those points, I'm generally pretty happy with this bottle. It's twice as large as my Nalgene 2L bottle but costs significantly less, and works about as well for my purposes. (Actually better, thanks to the size.)