Read more (PDF, English only) - Logitech
05/12/2014 - www.logitech.com
ight) the wave-shaped contour sets every key at a unique, carefully calibrated height to assure maximum comfort. The left (Esc, Tab, Caps Lock, Shift, Ctrl), right (Backspace, Enter, Shift, Ctrl), and center (5, 6, 7; t, y, u; g, h, j; v, b, n) portions of the key frame are set several millimeters higher
at a maximum variation of 4 mm than other keys, resulting in a gentle, undulating wave-shaped contour.