Key switching is typically based on an electrode and convex rubber cup system. When pressed, the electrode contacts the corresponding terminal and data are transmitted. With the HHK Pro, however, a circular cone spring systems was adopted. This system is based on an electric capacitance system instead of an electrode system. This leads to softer keystrokes and longer keyboard life.

Happy Hacking Keyboard Professional

The switching area is on the downslope while the key can be pressed. The structure leads to perfect key switching by inertial force and you feel much more better than before.
Key stroke is about 4mm. Key pressure is about 45g.

The key switches have soft-snap characteristics. The switch turns on when the key has been pressed approximately 2 mm, while the key can be pressed about 3.8 mm. Key pressure is about 50g.