Specifications: This apparatus is used for the study of ?Reflex action? which in definition, is the instant responsive abilities of the human body, ordered from the back spine or the brain. An example include hammering the human knee, the instant reaction when stepped on a nail, which this chart will demonstrate. The chart is activated by using LED with sound when stepped on a sharp object. 220V AC 50Hz. Size of the board is 80x12x200 cm. It is made of wooden MDH covered with Formica plastic.