Drilled Ball Set, Set Of 12, 1 Each

The Drilled Ball Set, Set Of 12 by United Scientific is an economical set of drilled balls for pendulum experiments. It contains two each of 25 mm balls in brass, aluminum, steel, wood, cork and copper, each with a 3 mm countersunk hole so cord knots can be recessed. Matched sizes let students change mass without changing bob size. The set is packed in a plastic storage box.