1-The COR is a constructed ball, externally made up of 3 resistant and flexible rubber hose rings, joined together.
2-The lightest CORES normally weigh between 1.1 lbs(500 grs) and 2.2 lbs(1kg). The heaviest between 5 lbs(2.3 kg) or more.
3-In the DUNI the COR varies in size and weight according to the category to which the players belong. The DUNI is played by categories.
4-The balls for training:
A) they can be even lighter or heavier.
B) can be even smaller or larger.