First choice slim steel water bottle is 100% rustproof. Our steel bottles are made of high-quality food-grade steel, making them ideal for storing and providing any liquid, including milk, water, juices, etc. The bottle has a capacity which is enough to fulfill your daily hydration needs while doing physical activities. The bottle fits in any bag making its size convenient in all aspects. Best usage for office/school/college/gym/picnic/home/fridge. The bottle has multiple uses, right from numerous outdoor activities like hiking, yoga exercises to using it for you office and work from home set up as well.