3. A KEYBOARD COMPRISING: (A) A PLURALITY OF REAR OPEN ENDED MOLDED HOLLOW PLASTIC KEYS, EACH KEY HAVING A FLAT BOTTOM SURFACE, A VERTICAL RIB, A HORIZONTAL ABUTMENT AND INNER SUPPORTING RIBS IN AT LEAST SOME KEYS, (B) A STATIONARY METAL BASE FOR SUPPORTING AND GUIDING ALL THE KEYS, THE BASE INCLUDING A LINED HORIZONTAL FLANGE WITH VERTICAL GUIDE SLOTS THEREIN FOR GUIDING THE VERTICAL RIB OF EACH KEY, THE FLAT BOTTOM SURFACE AND HORIZONTAL ABUTMENT OF EACH KEY SANDWICHING THE LINED FLANGE TO DEFINE STOP POSITIONS FOR EACH KEY, (C) A LINED HORIZONTAL BAR-LIKE FULCRUM COOPERATING WITH A RECESS IN THE REAR END OF EACH KEY TO PROVIDE A PIVOT POINT FOR EACH KEY, (D) A COIL SPRING FOR EACH KEY HAVING ONE END CONNECTED TO A STATIONARY SUPPORT AND THE OTHER END CONNECTED TO THE KEY IN FRONT OF THE FULCRUM, (E) A SCREW CARRIED BY EACH KEY AND ADJUSTABLY HOLDING ONE END OF THE COIL SPRING FOR ADJUSTING THE BIAS OF THE COIL SPRING, AND (F) AN ACTUATOR TAB EXTENDING FROM THE REAR OPEN END OF EACH HOLLOW PLASTIC KEY.