Non-Filled. There are commercial stress balls that are not filled, rather they are made out of a special pliable foam rubber called closed-cell polyurethane foam rubber. The manufacturer injects a special liquid into a mold, resulting in a chemical reaction that creates carbon dioxide bubbles.
Some stress relievers are made from closed-cell polyurethane foam rubber. These are made by injecting the liquid components of the foam into a mold. The resulting chemical reaction creates carbon dioxide bubbles as a byproduct, which in turn creates the foam.
If you dont no what air slime is it is a new method to make slime without glue!. Color Changing Gel Stress Ball– Liquid filled ball changes colors when squeezed
Infectious Disease Balls Main Image; No one expects Bubonic Plague!. Squeeze the ball hard & blisters will protrude from the bag; Relieves stress and .