The Clik Valve has the advantage that it has a ribbed surface.
This means that you can screw the Clik Valve on or off with your bare hands in 90% of cases.
You also have the advantage that you no longer have to screw on/unscrew the valve cap as with conventional valves. This means that the valve hardly ever comes loose and you have to screw it back on again.
A valve key is therefore actually not needed.