For the adults: These keep my hot drinks beautifully hot for ages, which is so important when you have little ones forever distracting you from getting to finish your coffee or tea, or are like me and have adhd and just forget you’ve even made one! Also, if you chuck a few ice cubes in with your cold drink they will last for hours upon hours. They also fit wonderfully in the car cup holder.
For the kids: These are a brilliant size for their water bottles - big enough to last them a few hours but not so big as to be a bulky pain to carry around. They are by my kids sides for every meal, live next to their beds overnight, and follow them around through school days. They are easy enough for them open the spout themselves by about 2-2.5yrs so they can take a swig whenever they are thirsty, and to open the lid off by the time they are in kindy (NSW) to fill up as needed during their time at school.
I should really buy some backups for when the kids inevitably lose theirs…