Battery Box, Model C Capacity_50mL Research-grade oxygen spectrum tube at

Research-grade oxygen spectrum tube at 26cm with a 10cm central capillary

and major vessels of the human heart

Used to step a class through wave superposition and beat frequencies

Shows oxygenated and deoxygenated blood paths between heart chambers and alveolar surfaces through seven hand-painted removable parts designed with medical-professional input

sized so the heavier D cell stays seated when student-built circuits are picked up

Battery Box, Model C Capacity_50mL Research-grade oxygen spectrum tube atUsed to enclose dry cells safely for student built circuits, this battery box adds insulated terminals and prevents short circuits from rolling cells touching exposed lab metalwork.