Abstract: A plurality of keys are mounted in parallel columns on a key supporting panel for reciprocation between upper, inactive positions and lower, active positions. Each key comprises a translucent core having a legend on its upper end, a conductor on its lower end, and an opening therethrough intermediate its ends. Each core is mounted for reciprocation at its lower end in a plastic sleeve, which is removably mounted by a flexible detent in one of the openings in the panel, and is surrounded adjacent its upper end by a flexible sleeve or hood which resiliently urges the key core to its upper position. In each column of key cores the openings in the latter register with each other, and an elongate electroluminescent strip extends through the registering openings and beneath the panel to prevent accidental withdrawal of the keys, and to illuminate the legends on a column of keys when energized.