Re: Share Your Personal EDC Here Luke, The Sigg bottle is pretty robust, it is aluminum but well built. The cap seal does go airtight, and after normal movement builds a little pressure making it harder to open, and when it is open, some (a few drops) of the water is forced out, no big deal really. Sigg does make an alternate cap for less than $6 or so, that folds over, so the twist handle is flush with the cap. The cap that it comes with is really solid though. I stared at them for quite awhile as well and finally bought, glad that I did.