A hula hoop is a toy hoop that is twirled around the waist, limbs or neck. The modern hula hoop was invented in 1958 by Arthur K. "Spud" Melin and Richard Knerr, but children and adults around the world have played with hoops throughout history. Hula hoops for children generally measure approximately 70 centimetres (28 in) in diameter, while those for adults measure around 1 metre (40 in). Traditional materials for hoops include willow, rattan (a flexible and strong vine), grapevines and stiff grasses. Today, they are usually made of plastic tubing.
I have used Hula Hoops for the separation of antenna wires for Ham Radio. The smaller size works best for fan dipols but are a little hard to find now. ..... Jack WB9OTX
from wikipedia
click for photo By