Water Bottles & Insulated Flasks

Of course! On decathlon.com.gr you will find a comprehensive collection of water bottles for hiking and camping to keep you hydrated on every excursion. Find simple aluminum and plastic (BPA-free) bottles, stainless steel thermos flasks, flexible water flasks, as well as hydration bladder systems (backpack bladders) for every kind of outdoor adventure.

Which material is best depends on your priorities on the mountain, as each excels in a different area! Stainless steel is the best choice if you want insulation and durability. It does not scratch internally, does not retain odors or tastes, and when it features a double wall, it works as a thermos. It is slightly heavier but offers top-tier longevity.
Aluminum is the ideal choice if you are looking for lightweight gear and value. It is extremely light in your backpack, but it does not offer thermal protection. It features a special internal coating (BPA-free) to protect the metal.

A quality stainless steel thermos flask maintains the temperature of its contents for 6 to 24 hours, depending on the model and external conditions.
Classic double-wall vacuum-insulated flasks keep your drink hot or cold for approximately 6 to 12 hours, while more advanced high-insulation models or large camping thermoses can keep the temperature stable for 24+ hours.
Extra Tip: To boost performance, fill the thermos with boiling (or ice-cold) water for 1 minute before adding your actual drink, in order to pre-condition the inner wall.

The capacity you need is calculated based on the duration of your route, the ambient temperature, and the possibility of replenishment.
For short hikes (1-2 hours) or as a supplementary bottle, the ideal capacity is 0.5 to 0.8 liters, while 1 to 1.5-liter bottles are the most popular and essential size for a typical day hike, as they cover your needs for a few hours without putting excessive weight on your back. The necessary capacity for all-day or demanding summer hikes, or for camping if there is no drinking water source nearby, is 2 to 3+ liters. In these cases, backpack hydration bladders (water reservoirs) that distribute weight properly are preferred.

The key difference lies in the safety of the water you consume. A regular hiking bottle serves strictly as a storage vessel, and you should only fill it with guaranteed potable, clean water from home or from controlled taps.
On the other hand, a filtered water bottle incorporates an advanced filtration system (usually with a hollow fiber membrane and activated carbon). It allows you to collect water directly from uncontrolled natural sources (rivers, lakes, streams), as the filter removes up to 99.99% of bacteria, parasites, and microplastics, while improving the taste, instantly turning it into safe drinking water.