The vertical displacement of the alphanumeric keys should be in the range between a minimum of 1.5 mm (0.05 in.) and a maximum of 6.0 mm (0.25 in.); the preferred displacement is in the range between
2.0 mm (0.1 in.) and 4.0 mm (0.15 in.).
Additional Information: Displacement variability between keys should be minimized. 5908