American Educational Ball and Ring Demonstrating Thermal Expansion - La Contesa Used to prevent door handle

Used to prevent door handle of opening doors from hitting and damaging adjacent wall

This boldly colored

no resoiling

extra weight backpack

V-Neck Front and Back

American Educational Ball and Ring Demonstrating Thermal Expansion - La Contesa Used to prevent door handleAmerican Educational Ball and Ring Demonstrating Thermal Expansion Brand: American Educational The unit demonstrates the expansion of metal when heated and its contraction when cooled When either the ball or ring is heated, the ball will not pass through the ring When cooled, however, the ball will pass through the ring freely The ball and ring are mounted on insulated wooden handles to protect hands from the heat