Hydration systems are now very popular for hiking, trekking, cycling, etc. A drinking system consists of a reservoir that is stored in an arbitrary or designed especially for hydration system backpack, and a tube with a mouthpiece, which is put forward. So, you can delete your thirst without disrupting his activity.
Deuter , Camelbakand Platypusare certainly among the best known brands. Mostly, the differences are between the individual models in the style of the closure and the technique of the mouthpiece. Above all, the CAP role in cleaning and drying of the reservoir. So, deuter offers a clamping lock that opens over the entire upper side of the bag. Of course considerably facilitate maintaining the drinking system. Otherwise it looks for some models of Platypus , here the hydration bladder possesses only a small screw cap, what makes thorough cleaning of course something difficult.
The mouthpieces are similar in principle, want to drink it is necessary on the valve which consists of soft rubber, bite.
Even if the reservoir, the hose and the valve are made of plastic, so the water with me so far never somehow tasted after plastic. I have experience with Platypus and deuter, whereby the deuter system much better I like (handy lock and safe drip valve).
The bag there is usually 1, 2, or 3 liter versions, and are available from approximately 20 euros at allsetbackpacks.com (only hydration system without special backpack). It also offers special backpacks for hydration systems, or backpacks with special Trinksytemfächern. The bag can accommodate but can easily into the top pocket of a traditional backpack.
At Wikipedia , I have read, by the way that a Camelbak belongs to the standard equipment of the American soldiers. On the Internet I found also this photo where you can clearly see the bag on the back of the soldiers.
A hydration system is a part of my gear I no longer want to miss.