They have 50's, 70's, 100's, 150's, and 300's. A lot of folks that breed pond fish or larger cichlids will set up the 300's outdoors for the summer. They nest inside each other, just like paper cups, so when not in use they take up much less space. I fit seven of the 150's in the back of a Ford F-150, got them used from a breeder who was retiring. A stack of seven sits about 5' tall, and takes up the floor space of one tub.