Unlike most travel bottles which must be turned upside down to squeeze out their contents, these are designed in a light bulb shape with the opening at the base of the container. No shaking or waiting for contents to be accessible on account of gravity. Better yet, the use of flexible silicone — instead of hard plastic — allows you to depress the container easily, getting out every last drop of its contents, like a tube of toothpaste. The extra wide mouth makes filling the bottles much easier and quicker. Best of all, the bottles were designed in accordance with TSA standards: they are transparent enough to be considered clear and hold 2 oz each. I have flown with these several times with great results. I simply put them in a clear plastic zipper bag and drop them in the security bucket with my shoes and am on my way. They’re on the pricey side, but are so easy to use I won’t be switching back to those hard plastic travel bottles (even if the TSA eases up).
[Note: A good alternative to these are the HumanGear GoToobs availalbe at Amazon in a range of sizes.--OH]