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Frequently Asked Questions.

FAQs about FLSK.


Inspired by the Scandinavian design style, the FLSK team has designed a minimalist, purist drinking bottle. FLSK is pronounced "flask" ([flɑːsk]) and is the English word for "bottle".

What's really special about the FLSK is its insulating performance. It keeps your drink ice cold for 24 hours and hot for 18 hours. So when you step out of the house in the morning on a warm summer day, you don't have to worry at all about your drink getting warm and then not tasting good. It's the same in winter: If you have a hot drink with you, you can warm up on it all day long. 

No matter where you buy the FLSK - you always get it in a high-quality tube box packaging. This protects against scratches and looks so good that you can give the FLSK directly as a gift.
The FLSK is the revolution of the conventional drinking bottle - simple from the outside, but ultra functional from the inside. It is made of pure stainless steel, so it is completely rustproof, odorless and tasteless. 

For you, this means: You can fill it with anything you like. Whether it's tea, maybe a beer, sparkling mineral water or even champagne.

To enjoy the perfect FLSK moment at any time, it's best to follow these tips and tricks.  

The FLSK water bottle is available in nine colors and four sizes. If you're still not sure which FLSK you like best, you can check them out live in one of the over 800 stores in Germany, Austria and Switzerland. 

Convince yourself.

FLSK 350 ml
FLSK 500 ml
FLSK 750 ml
FLSK 1000 ml
Diameter bottle opening 3,2 cm 3,2 cm 3,4 cm 3,4 cm
Weight incl. lid 270 g 320 g 420 g 500 g
Height incl. lid 21,1 cm 25,5 cm 28,6 cm 32,0 cm
Height without lid 20,5 cm 24,8 cm 28,0 cm 31,5 cm
Diameter FLSK 7,1 cm 7,1 cm 8,0 cm 8,9 cm

It is better not to clean the FLSK in the dishwasher. Due to its conical shape, hardly any water gets inside the bottle, and the paint can also be damaged. 

The daily cleaning of the FLSK is nevertheless very simple. Unlike conventional thermo bottles it contains no glass inside that could break and is therefore much more robust. The FLSK stainless steel drinking bottle can be conveniently rinsed with boiling hot water and a little dishwashing liquid. Regular cleaning is important here, so that substances such as teein or caffeine cannot settle in the first place. If something does get deposited, our cleaning balls or a commercial denture cleaner from the drugstore will help. 

Here you can find detailed information about cleaning your FLSK water bottle. 


We like to keep you up to date with all the latest news about FLSK - promotions, new products and much more. Simply register for our newsletter and you will always be well informed.

We are sorry if your favorite FLSK should be sold out in our online shop - your favorite is in great demand, you must have very good taste! We will of course try to restock as soon as possible and offer the full selection in the store. 

VICC® stands for Vacuum Insulated Copper Coating. The FLSK drinking bottle combines unique design with high functionality. It is made of stainless steel and maintains the temperature through the VICC® technology longer than other thermo bottles. Between the double-walled stainless steel is a vacuum layer, and in addition a copper coating guarantees the preservation of the temperature. Due to the narrow opening and the double-insulated lid, the FLSK drinking bottles are 100 % leak-proof. 

Learn more about the new technology of the FLSK stainless steel thermo bottle here!

The FLSK thermo bottle is also very suitable for children. The small size with 350 ml capacity is very light and small and therefore suitable for children's hands. When preparing baby food, hot boiled water can be filled into the FLSK stainless steel drinking bottle to always be able to prepare baby milk during outings. It is therefore ideal in its function as a baby insulated bottle. For toddlers, fruit spritzer or juice can be transported in the FLSK thermo bottle for kindergarten. Also at school, the FLSK drinking bottle becomes a companion. The older ones can then also take a larger bottle - after all, a balanced drinking pattern is more than important for the development of the little ones!

Yes, in the FLSK Online Shop you can give your FLSK a very individual touch with a personal engraving. You can find all information about engraving at a glance here. 

FAQs about the Movement.


Since our foundation of FLSK in 2015, we have been intensively considering what "sustainability" means to us. As a result, we have created the "Movement". With it, we show what holistic sustainability means to us. With the areas "FLSK moves you", "FLSK moves itself" and "FLSK moves more", we are taking the path to the ecological-social best possible. You can find out more here.
We fabricate FLSK and muki in the province of Zhejiang/China. Since there is currently no infrastructure for the production of stainless steel products in the EU, we cannot produce our products cost-effectively on a regional basis. In concrete terms, this means that the FLSK drinking bottle would cost over 200 euros otherwise. In contrast, production in Zhejiang is highly professionalized. This is demonstrated in particular by the very short production distances. The entire production of FLSK and muki takes place within a radius of 50 kilometers - from the steel sheet to the final packaging. Comparably short distances are impossible in Germany and the EU.
In China, we make sure that production is as fair as possible. We have a long-term partnership with our suppliers. Personal exchange is particularly important to us. In addition to regular on-site visits by Quentin (CEO) and Patrick (product development), we have a 5-person FLSK team in Zhejiang. Furthermore, external audits of the Business Social Compliance Initiative (BSCI) are conducted annually at all of our direct suppliers. This allows us to objectively classify working conditions as mostly "good". This means that employees are voluntarily employed under contract, can participate in elected employee representatives, receive the regional minimum wage or more, and are paid up to a 200% premium for voluntary overtime. In addition, all employees are provided with protective equipment. You can read more about this here.
The packaging of FLSK and muki is composed of the cardboard tube, a reusable fabric bag and a transport cover made of plastic. This additional packaging material is necessary to protect our products from transport scratches. Since 2021, we have been using only FSC MIX material for the cardboard tube. By the end of the year, we have resolved to eliminate single-use plastic. Instead, we want to use renewable raw materials or recycled material. You can find more information here.
FLSK products are transported from China to Germany in the most environmentally friendly way possible. Basically, there are four modes of transport to choose from: Airplane, truck, ship and train. Since water and rail logistics have the lowest environmental impact, we transport half of our products by ship and half by train. For water transport, we work with the GoodShipping Initiative. By filling up with biofuel based on used cooking oil, we reduce CO2 emissions to zero. For train transport, we will offset emissions through certified climate protection projects from 2020. You can find out more here.
The FLSK drinking bottle and the muki snackpot are made of type 304 stainless steel, also known as 18/8 stainless steel. This stainless steel has a very high quality and is also used for medical instruments or in food processing. It is food safe and thus helps to resist smell and taste residues.
18/8 means that the stainless steel contains 18% chromium and 8% nickel. Both are alloying elements that make the stainless steel resistant to corrosion and acid. This means that our products are guaranteed rust-free. The plastic components of our products are polypropylene (PP), polystyrene (EPS) and movable silicone in the sealing rings. These are necessary to ensure the insulating and sealing function in the lid of the FLSK and the TriZone ThermoGuard of the muki.

Both products are BPA free in their entire material composition, contain no plasticizers and are thus completely free of harmful substances. This makes them the perfect reusable alternative to plastic products.

FLSK and muki are designed to give you many years of pleasure. If at some point their last days are numbered, take your daily companion to the recycling yard. Separate FLSK and muki according to materials. This increases the chance that the majority can be recycled. After all, the stainless steel components in the metal waste can be melted down and used for new products.
We have prepared a comprehensive carbon footprint. In 2019, our so-called corporate carbon footprint is 916 tons of CO2. This carbon footprint includes not only FLSK and muki, but our complete product range and all business activities - from business travel to the energy consumption of our office. In the medium and long term, we want to reduce our emissions directly. Our biggest lever is the use of recycled steel, which we intend to increase over the next few years. We have already been able to achieve small savings: Our office has been supplied with green electricity since 2020 and shipping is CO2-neutral due to the use of biofuel. From 2019, we will offset all emissions that we were unable to avoid. We are currently identifying suitable offsetting projects. So it won't be long before not only our products, but FLSK as an entire company is "climate neutral". Including shipping to your home. You can find everything about our carbon footprint here.
Since 2017, we have been donating one percent of our sales. This money is managed in the FLSK Future Fond by the Future Foundation for Development in Bonn. So far, the six-figure sum has been able to actively drive sustainable energy supply in Germany. In 2021, we want to use the money to directly support people who are committed to the environment and society. This will transform big ideas into moving projects. Our three focus areas are development cooperation, education and research. Find out more here.

FAQs about muki.


Congratulations, you have made an excellent choice and have chosen the muki as a snack pot that will accompany you every day.

 We have prepared detailed instructions and many tips for you so that you can enjoy your perfect muki moment every time. 

The best way to clean your muki snack pot is with lukewarm water, a dishwashing sponge and some detergent. Be careful with color intensive food like berries or similar: You should first rinse the TriZone ThermoGuard with cold water to prevent discoloration. Both sealing rings and the pressure valve can be removed and cleaned individually.

To avoid odors or discoloration, you should clean and dry your muki after each use. We recommend not to put the muki in the dishwasher, otherwise the powder coating could be damaged. 



Weight320 g
Height 15 cm
Diameter top 9,5 cm
Diameter bottom 6,5 cm
Cup filling quantity 300 ml
Lid filling quantity 250 ml

The muki snack pot can be personalized with a laser engraving in the online shop. This is especially practical if each family member has their own muki, because this way nothing gets mixed up in the kitchen. An engraved muki is also a very special, personal gift.

FAQs about the additionals.


There is currently no neoprene bag for the FLSK 350 ml. However, the small FLSK fits perfectly into the FLSK neoprene bag 500 ml, where it is protected from scratches and shocks.

In every new FLSK drinking bottle there is a spare sealing ring to change. If you need a new sealing ring, please write a mail to hallo@flsk.de.

FAQs about our special deals.


You can order the FLSK drinking bottles in the sizes 500 ml, 750 ml and 1000 ml as a package with a matching neoprene bag and the cleaning balls. You save 9,50 € compared to the single purchase. 

This is not possible with the FLSK drinking bottles in the 350 ml size, because there is no neoprene bag in this size (yet).

FAQs about your order.


You can redeem your voucher code in the shopping cart or in the order process. Simply enter your code in the "Coupon code" field and then click on “Use code” to the right. The discount will then be displayed in the overview and the total amount will be updated. Please understand that discount codes will not be applied after you submit your order and cannot be combined with each other.

We understand very well that you can hardly wait for the arrival of your eagerly awaited package after your order in our online shop. That's why you will receive a mail with a link to DHL tracking after we have handed over your package to DHL for delivery. With the link you can track your package and find out where it is at the moment and when it is expected to be with you. If you have not received this link yet, we are most likely processing your order in our logistics center. 

You are not satisfied with your order? We are sorry. You have the right to cancel your order within fourteen days without giving any reason. The day on which your package was delivered to you or a third person is decisive for this. Please note that goods can only be revoked if they are unused and unengraved.

As soon as we receive your return, you will of course get your money back. 

We are always working to improve our service and look forward to hearing from you about what went wrong and the exact reason for your cancellation. We are already looking forward to welcoming you back to our online shop soon!