I have been selling the 500ml aluminium water bottles for several years now, averaging over 100 a month over the last couple of years.
Over this time I have identified a number of issues that I think need raising should you currently be printing/selling these or are considering stocking them. These issues were brought to my attention by my customers and I have now received numerous complaints regarding each individual issue.
Firstly, the straps used to hold the lids onto the sports drinking type caps are slightly too short. If you tighten the cap onto the bottle the lid 'pops' off as the strap tightens slightly and physically pulls the lid off. Upon bringing this to the manufacturers attention the issue appeared to be quickly rectified with subsequent lids having a slightly longer strap thus solving the issue. Unfortunately it appears that manufacturers are again supplying this faulty lid as recent stock has suffered from the same issue.
Secondly. There is an issue with the vast majority of these bottles (in my experience) in that the water does not flow properly. This was brought to my attention earlier this year when several customers complained of excessive 'bubbling' when the child drank from the bottle using the sports type cap. If you fill the bottle with water and physically drink from it you'll see, or rather 'feel' the problem. Try this with a few different caps and you may well notice different results. The occasional cap performs properly with the water flowing as it should. The vast majority of caps will demonstrate the 'bubbling' issue that is being reported to me more and more.
Lastly but possibly most importantly. Whilst I must stress that this has only affected a very small number of sports lids I feel it is very important that you check each lid before selling on. Upon pulling the white nozzle from the lid to start drinking, the small nozzle completely comes away from the lid, separating from the main section. I would like to think this problem was very limited but ask that you double check every lid, I'm sure you'll appreciate the possible implications of one of these being swallowed.
If you have these bottles in stock, please carry out the drink test on the sports lids and post your results. I genuinely hope that you have unaffected stock but as I have been testing these for a considerable amount of time it's quite possible that you may find problems. Carrying out tests with family/friends they didn't initially notice the problem until I put a 'good' working lid on and got them to drink from both this and a faulty lid. It was then immediately noticeable.