convenient bottle / water bottle

Convenient bottle is designed for the workers who are always working outside. It is inconvenient for them to carry a bottle of water aside, but water is quite necessary for them. They must feel extremely thirsty when they have not drunk a little water for a long time. However, it may be more seriously if it happens in a hot summer. It is our responsibilities to care for them. So there comes the convenient bottle. Workers just need to buckle the bottle around at the waist. Then, they can drink cool water whenever they want.