5 liter

it must do in the 20cm cube, you have to have the place of storage.
refilling the small bottle is not practical. you must replace the cap that comes with the can with a cap with a long tip but did not cap to the block so you should remove it every time to plug the other hand, and what he it has in it is wasted. it would be enough to put a long nozzle with a small cap that is at the end, will be easier. Not recommended for grandmas or not very strong women like me, it was my husband who did it because it's quite heavy and you have to press hard to ensure that the product.