Hydro Bowls, by Canine Hardware are waterproof, durable and snaps closed into a easily stored compact size. The snaps also enable the Hydro Bowls to be snapped onto any leash, backpack, bicycle, etc. The medium size holds 5 cups of water and is available in assorted colors of red, blue, purple and yellow. Please specify first and second color choices during your check out process as color availability may vary.