I travel at least 5-7 times per year between work and personal trips so it's important to find good travel bottles that don't leak and that you can reuse for a while, they can get expensive. I've used these on at least 3 trips that involved flying... usually the altitude will cause the cheap bottles to leak in flight... and these have been great. They have not leaked liquids like shampoo and conditioner and I've been able to refill them multiple times. These are definitely a money saver, refill these instead of buying the costly travel size products!