1lb Painted Metal Inertia Ball with 3 Eye Bolts Subcategory_Eye Protection running as either water turbine

running as either water turbine or motor-driven pump for fluid-based energy-conversion work

used as the standard positive partner to ebonite in triboelectric investigations

providing low-temperature-coefficient reference values for Ohm's-law and bridge calibration work

Twelve-inch black insulated 4mm-stackable lead with banana plugs at both ends

a 6V buzzer

1lb Painted Metal Inertia Ball with 3 Eye Bolts Subcategory_Eye Protection running as either water turbineOne pound metal ball painted black with three fixed eyebolts of 3 8 inch inner diameter, configurable as a heavy pendulum bob or a demonstration mass for Newton's first law setups.