In FLSK, water and other drinks will stay refreshingly cold even after hours of hiking. If it’s winter, your tea will stay hot for 18 hours and supply you with much needed inner heat. If you would like to strap FLSK to your bag, it can happen that it slams against a rock or branch, but no worry, FLSK is robust enough to withstand even the strongest hits. FLSK STNLS will stay with you for a long time, and you will miss it dearly in case you forget it at home. The environment will also thank you, since there is no chance of plastic lying around in the countryside with FLSK.