I have given several Rolla Bottles away as gifts. And I have several myself ... One for my bike. One for my backpack. And 2 that are filled with sand and water to act as weights. Why weights? Because I couldn't get to a shop to buy weights (for strengths-training) during lockdown so I had to improvise :-) No leaks. Easy to use. Easy to wash. They are great and I highly recommend them.