My daughter loves playing with these pop tubes. She likes the sound that they make when she stretches them out. She also likes to take the stretchy strings and let them slide down the inside of the tubes. She has been playing with these daily since we received this set. The set comes with 6 pop tubes, 6 large stretchy strings and 3 small stretchy strings. The tubes are about 9 inches long and stretch out to about 28 inches long. They can also be connected end to end to each other.This is a good toy for sensory play, focusing concentration or stress relief.