These inexpensive water tanks are a popular and practical solution to the storage of water on-board where the installation of rigid tanks is not possible. They are flexible, light and adapt to the available space using the double envelope principle with an easily removable high frequency welded inner chamber and tough outer envelope. 1 1/2 inlet on the top and 1/2" outlet on the bottom of the tank, both with "O" rings. When full the tanks are 25cm high. We carry 3 sizes in stock. Spare inner chambers available.