Great for reminding you to drink
I had considered getting the $50+ bottle that lights up to remind you to drink. This works the same way for a fraction of the price.  Plus you can move it to any cup or bottle you want.  I have not had a problem with it fitting any cup or water bottle.  I have another one from the same company that has lasted over a year.  It is really a great product for the price.
Rating: 5 stars