These are a couple of tools to help tighten the MC4 Solar panel connectors, they are not for proffesional use everyday but just the occasional user.
there is a holder to slide the body of the connetor into and a compression ring type wrench to grip the nut with.
*** Updated Wrench added ***
Added the STL for a modified wrench with a feature that allows you to press the release tabs to disconnect the two halves when connected.
The author marked this model as their own original creation.