A large volume drinker for a cage. The three liter ( 101 ounces) is meant for cages with a number of pigeons or a large chicken or two. The Large Cage Drinker goes inside the cage and stands on its own, but also has a metal attachment with clip; to clip on the cage wire to hold in place.  The drinker is also handy if you need to leave for a few days and you need a larger amount of water available to the birds in a cage.