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
Dry Field Mapping Kit, includes cork-covered base, 30cmx26cm; pad of 25 sheets pre-printed conductive paper 28cmx21.5cm; pad of 100 sheets preprinted paper for drawing fields; ten metal-headed push pins; a silver conductive pen