Simple: Because the terminal blocks are delivered with preloaded spring. Stripped wires can be easily and safely inserted into the clamping point without further preparation. The conductor is contacted in the clamping point with a clear “click“. The triggered clamping point is additionally signaled visually by a raised pusher. By pressing the pusher, the conductor can be quickly and easily released at any time and the clamping point pre-loaded again. It could not be any easier.