Adjustable clamping levers GN 300.1 are preferably to be used when the clamping range is limited or a certain clamping position is desired. The threaded insert is detachably connected to the handle by a notch toothing. By lifting (pulling) the handle, the notch teeth become free and the clamping lever can be swivelled into the most favorable clamping position. When "releasing", the handle automatically locks back into place.