Many people don't wish to take full-size versions of toiletries, medications, or other items when they are traveling, so they purchase smaller travel bottles to carry these items instead. There are a number of different types of travel bottles available to store these different items in, featuring different types of caps for convenience. Though they are also available in many different sizes, it is important to check airline regulations before attempting to carry any bottles on a plane; they generally need to be under a certain size and stored in a clear plastic bag if they will be carried on as liquids, otherwise the airline staff at the gate will simply throw the items away.
The most common types of travel bottles are simply small, clear plastic bottles that will be able to store a few ounces of liquid, such as shampoo, conditioner, or body wash, among others. Most have simple twist-off or snap-off caps, but are designed not to crack or come open with heavier use, such as when a bag is stored in a plane. Other types of travel bottles are available as well for storing different types of liquids; these include spray bottles, pump bottles such as those used for hand soap, or bottles with a dropper or squirt top. Squeeze bottles are also available.
For items such as medication or vitamins, small plastic jars exist as well. These may come with childproof lids, or lids that are easier to remove for people who have trouble with twist-off caps. If traveling internationally, however, is is better to keep medications in their original packages together with any relevant prescriptions. It is also important never to mix different kinds of pills in the same container.
Though all these different types of travel bottles may be purchased individually, it is also possible to buy them in kits, which will come with numerous bottles in different sizes and styles. These are often designed to be ready for airline travel, and may even come with the standard sized plastic bag to store them in if they will be carried on the plane. Keep in mind that these size regulations generally do not apply to bags that will be checked.
Travel bottles exist for other purposes as well, such as holding beverages. These are typically also made of sturdy plastic or aluminum, and are often now free of bisphenol-A, or BPA, which is a concern in some plastic bottles. Travel versions of baby bottles exist as well. Larger bottles can typically only be taken on airplanes if they are empty, but they may certainly be used for other types of travel, and are better for the environment than constantly purchasing new bottles of water.