myColdCup Ice Stick - Large (8oz) for Wide Mouth Water Bottles, Beverage Dispensers, Water Jugs, Growlers - BPA-Free (Set of 4)

These are the perfect solution for keeping my Nalgene water cold!First, they fit exactly into the wide mouth of my 32oz Nalgene bottle. You do need to pay attention to the fill “line” though for them to fit right. If you leave a half inch, as suggested, you have to wiggle them a bit to fit in the bottle. I usually leave about an inch of room and they slide in easily when frozen.They occupy about 8oz, so keep that in mind when filling up your bottle before dropping one of these in. And they last several hours (4ish), before totally melting — but, as stated, you can drink the melted water and it’s still nice and cold! The set of four is great too, so I can use two each day (swap one out midday for a fresh, frozen one to keep my refilled water cool) and have another two ready to go for the next day.Getting them out is really easy too — just tip your bottle upside down and wiggle it a bit for easy removal.So happy with this purchase!

While I do own nalgene bottles that I could use these in, my main reason for buying them was medical. I've got some mild plantar fasciitis and my doctor told me to put cylinders of ice to roll back and forth on the bottom of my feet. It sounded crazy, but I missed that day of medical school (and all of the others, by the way). So, I searched Amazon and sure enough found these. They really do work to distribute cooling along the bottom of your foot. It also may be stretching the muscles somewhat and giving a cooling massage to the bottom of my feet. I highly recommend these if you're having any issues with the bottom of your feet.

Thee are a great idea, but they’re a teeny little bit wider than the listing shows. I use very wide-mouth 32-oz water bottles, and these would’ve slid in and out fine if the measurements were accurate. As is, I could’ve forced them in, but getting them out would’ve been a nightmare.Would work well for things like insulated lunch bags, but I suspect VERY few water bottles can accommodate these.

Do not use these for your lunch boxes to keep food cold if you lay them down they can leak a bit but not terrible. I used them for my drinks and they keep the cold, if you start with cold water it keeps them cold for hours. I really enjoy using these, I didnt know it came with four of them though which is nice!

These work great . I drink soda most of the day, give me a break it's my only vice, and prefer it very cold. I use the big bubba 50 something ounce insulated mug. Ice cubes even the jumbos dilute too much, faster than I can finish usually. Two of these go in and the soda stays cold for hours. I tried the size up but it was too tall for the bubba. Not the sellers fault, should have measured. I rinse 2 off, swap with frozen ones, easy fix. By the time one set melts the other is frozen solid. Very happy.