You have to love the individual aquarium/terrarium for your classroom or home. The 1/2 gallon is perfect for a single Chinese fighting fish. Best of all, each is made of plastic that is sturdy for all types of use. The molded "feet" on the bottom keep them from harming furniture. These are a great value and make an excellent learning tool for children of all ages. All grades. Ages 5 above. Set of 15.