So now I have tried all kinds of terminals. In my opinion, these are here the best affordable for 2.5² mm. 4²muss be introduced either laterally or is isolated from approximately 4 cm, because the insulation does not fit into the connector. The assembly is based on the simplest and quickest principle and without tools. For 4²mm I would rather take Nakamichi- plug, but this is a matter of opinion.