The canteen features a clip on the back to secure to your person, and the long 36 in drinking tube offers maneuverability. The shut off valve prevents contamination and stops water from leaking. The large diameter tube gives you a higher volume of water on demand, and prevents light-headedness from vigorous slurping. Holds 1 quart. This is an essential component to any mask. You need to hydrate, especially during a contamination event. And your mask loses 100% of its effectiveness if you have to pull it off to drink. Made in the USA.