Don't keep drink cold very long
341203
They are hollow and don't stay cold long at all. I wouldn't recommend unless you chill your liquor. Choose a soapstone or granite instead!
4591554
They don't stay cold long at all.  I use this in a pack it insulated bag and within 4 hours they are all water and just cool.  I would not buy these again
331763
Liquid stays cool, not cold, and certainly not for 24 hours. 8 at best. Ice is gone within 2. It's a good product but not great.
1988199
I travel  to  work and  have several cups similar to this.  The  slim  cruiser I  chose  due  to the  shape and  size. I needed a  narrow  bottom  for  certain  cup holders.  The  cup  looks  very  nice.  The  cup  handles well and  the lid is  a great  fit.  I  just  do not think  it  keeps the  beverages as  cold as  some  other  brands  do.  I  questioned this  more than  once and decided  to  fill  it with  cold  coffee and  ice  today  to see if the ice  melted down  and  the coffee  stayed  cold....Ice melted and  coffee  was  chilled but  not  cold.  This was over a  4  hour  period ,  I  traveled  to work and  then was  inside  an  air conditioned office.  80  some  degree  days  here  and  not yet  very  hot  for the  summer!
2557469
These are good and do help keep my Snapple Iced Teas cold, but not for very long, about an hour.  They are neoprene so it's a thin insulator.  I'm happy with it.  One of the neoprene insulators didn't have a string in it, but perhaps it's a fluke.  It's still worth it overall for me.
2800397
It keeps my drink warm but I wish the temperature is higher
3533276
Do not stay cold long enough. Maybe 2 min. Better off buying those plastic ice cubes that don't melt.
207044
I ordered these for my dad.  He likes the color, size, etc., but they don't do what I ordered them for...keep drinks cold.  He even put just ice cubes in, 4 hours later he had just water.  That would work with any glass.  They don't seem to be very insulated.
4365699
The only thing you will need to keep cold drinks cold for 24 hrs.  Or keep it warm for 6 hrs.
2871132
The cups are great in size and they fit in most cupholders. The problem I found is there isn't much difference in the amount of time your drink stays cold v. any other insulated cup. I will go back to using my "real" thermos which isn't anything fancy, but at the end of the day it's what works. I think this is a perfect cup for "normal" use. Personally, I "need" something where the ice doesn't melt for at least 6 hours.
2031450
These bottles keep drinks cold for over 12 hours....it's really quite amazing...but even this larger 16 oz size is too small. When you've got part of the bottle filled with ice, the fluid goes too quickly and you are left still thirsty.
2228745
They are beautiful and keep drinks cold longer than a glass vessel, but not nearly as long as their post suggests.  A half hour maybe, but four hours?  No.
2836519
Love the straw and that this keeps my drinks colder longer, but it's not totally insulated. The bottle still sweats and loses insulation, but just because it's not perfect doesn't mean it is not a good product.
4347529
The cubes get cold quickly & stay cold. While they won't get your drink "ice cold", they will chill your drink to an enjoyable temperature & keep it there for 10-15 minutes. Using already chilled beverages will elongate the cubes' effectiveness. Cubes must be hand washed & not exposed to heat.

I would definitely get these again, & more of them would allow them being used in larger glasses for tea, soda, water, etc.
4183986
love these, they do keep drinks cold for 24 hours... but, the opening is small and hard to get ice in.
4940753
These bottles are okay but the lid is not insulated so will sweat when having cold water in it, and sweat means that it's losing its cold and being transferred out of the bottle. I assume this would be the same way with hot water as well although I've never used it with hot water. I've found that unless you fill it with tons of ice the water does not stay cold for 24 hours. I would say cut that in half more like 10-12. I got a double pack at Costco for a really reasonable price so will keep it. If I had paid the prices on here for them, I would have immediately returned it.
4101080
The insulation does not keep cold liquids very cold for more than about 2 hours.  The Aladin insulated similar container keep liquids very cold for more than 4 hours.