The photronic cell used in electrical experiments to demonstrate control of currents and lighting.Black bakelite circular case with two socket pins. Circular open top with tiny copper pins around the edge. Box Black and whiteName of maker and item: WESTON PHOTRONIC CELL MODEL 594 PAT PEND NEWARK N J U S Aweston, photronic cell, socket pins, copper pins, bakelite, experimental, electrical currents, lighting