Harmonic Motion Spring, ideal for demonstrations or hands on experiments in the physics classroom, 7 inches (18 cm) long with a maximum diameter of 1.4 inches (3.5 cm) and a spring constant (k) of 9.6 N/m
Ray box, simple, safe and sturdy source of projected light for many classic optics experiments, produces parallel convergent rays across a plane horizontal surface and the rays are intense enough to be traced in natural light. Built in solid aluminum extrusion casing, 100-240V 50/60 Hz